View source for Mercedes-Benz W126

{{short description|Car model}}
{{For|complete overview of all S-Class models|Mercedes-Benz S-Class}}
{{Infobox automobile
| name = Mercedes-Benz W126/C126
| image = 1987-1991 Mercedes-Benz 300 SEL (V 126) sedan (2010-04-03) 02.jpg
| caption = 
| related = [[Monteverdi Tiara]]
| layout = [[FR layout]]
| assembly = Germany: [[Sindelfingen]]<br/>Malaysia: [[Johor Bahru]] (OASB)<ref name="Oriental Assemblers Sdn. Bhd., History 1967-1987">{{cite web|author=Leeps |url=https://news.google.com/newspapers?nid=1309&dat=19890604&id=tKFUAAAAIBAJ&pg=5932,900833&hl=en |title=Rust Busters |publisher=[[New Straits Times]] |date=4 June 1989 |access-date=3 May 2015}}</ref><br />South Africa: [[East London, Eastern Cape|East London]]
| manufacturer = [[Daimler-Benz]]
| production = {{ubl | December 1979 – October 1991 (sedan) | September 1981 – October 1991 (coupé) | 1981–1994 (sedan, South Africa) | 1981–1991 (coupé, South Africa)}}
| predecessor = [[Mercedes-Benz W116]] (sedan)<br />[[Mercedes-Benz R107 and C107|Mercedes-Benz C107]] (coupé)
| successor = [[Mercedes-Benz W140]]<br />[[Mercedes-Benz C140]] (coupé)
| class = [[Full-size]] [[Luxury vehicle#High-end luxury.2Ffull-size luxury cars|luxury car]] ([[F-segment|F]])<br />[[Grand tourer]] (C126)
| body_style = 4-door [[Sedan (car)|sedan]]<br />2-door [[coupé]] (C126)
| transmission = 4-speed [[4G-TRONIC]] [[Automatic transmission|automatic]]<br />4-speed [[Manual transmission|manual]]<br />5-speed [[Manual transmission|manual]]
| engine = {{ubl
  | '''[[Petrol engine|petrol]]'''
  | 2.6&nbsp;L ''[[Mercedes-Benz M103 engine|M103]]'' [[Straight-six engine|I6]]
  | 2.8&nbsp;L ''[[Mercedes-Benz M110 engine|M110]]'' I6
  | 3.0&nbsp;L ''[[Mercedes-Benz M103 engine|M103]]'' I6
  | 3.8&nbsp;L ''[[Mercedes-Benz M116 engine|M116]]'' [[V8 engine|V8]]
  | 4.2&nbsp;L ''[[Mercedes-Benz M116 engine|M116]]'' V8
  | 5.0&nbsp;L ''[[Mercedes-Benz M117 engine|M117]]'' V8
  | 5.5&nbsp;L ''[[Mercedes-Benz M117 engine|M117]]'' V8
  | '''[[Diesel engine|diesel]]:'''
  | 3.0&nbsp;L ''[[Mercedes-Benz OM617 engine|OM617]]'' [[Straight-five engine|I5]]
  | 3.0&nbsp;L ''[[Mercedes-Benz OM603|OM603]]'' I6
  | 3.5&nbsp;L ''[[Mercedes-Benz OM603|OM603]]'' I6
  }}
| designer = [[Bruno Sacco]], Werner Breitschwerdt (sedan: 1975, 1976; coupe: 1977)
| wheelbase = Sedan (SWB): {{convert|2935|mm|in|1|abbr=on}}<br />Sedan (LWB): {{convert|3075|mm|in|1|abbr=on}}<br />Coupe: {{convert|2850|mm|in|1|abbr=on}}
| length = Sedan (SWB): {{convert|4995|-|5020|mm|in|1|abbr=on}}<br />Sedan (LWB): {{convert|5135|-|5160|mm|in|1|abbr=on}}<br />Coupe: {{convert|4910|-|4935|mm|in|1|abbr=on}}
| width = Sedan: {{convert|1820|mm|in|1|abbr=on}}<br />Coupe: {{convert|1828|mm|in|1|abbr=on}}
| height = Sedan (SWB): {{convert|1430|-|1437|mm|in|1|abbr=on}}<br />Sedan (LWB): {{convert|1441|mm|in|1|abbr=on}}<br />Coupe: {{convert|1406|mm|in|1|abbr=on}}
}}

The '''Mercedes-Benz W126''' is a series of passenger cars made by [[Daimler-Benz AG]]. It was marketed as the second generation of the [[Mercedes-Benz S-Class]], and manufactured in [[Sedan (automobile)|sedan]]/saloon (1979–1991) as well as coupé (1981–1990) models, succeeding the company's [[Mercedes-Benz W116|W116]] range. Mercedes-Benz introduced the 2-door C126 [[coupé]] model, marketed as the SEC, in September 1981. This generation was the first S-Class to have separate chassis codes for standard and long wheelbases (W126 and V126) and for coupé (C126).

Over its 12-year production (1979–1991), 818,063 sedans/saloons and 74,060 coupés were manufactured, totaling 892,123 and making the W126 by far the most successful generation of S-Class to date, and the longest in production.<ref name=W126history/><ref name=S-Klasse>{{cite web|url=http://www.s-klasse-club.de/gb/geschichte-126.html |title=S-Klasse Club information |access-date=13 May 2007 |url-status=dead |archive-url=https://web.archive.org/web/20070928010431/http://www.s-klasse-club.de/gb/geschichte-126.html |archive-date=28 September 2007}}</ref>

== History ==
After the debut of the W116 S-Class in 1972, Mercedes-Benz began preparing for the next generation S-Class, in October 1973. The project, code-named "Project W126", aimed to provide an improved ride, better handling, and improved [[fuel efficiency]]. The oil crisis of 1973 and increasingly stringent emission and safety regulations in the United States had an important influence in developing the W126 for reduced emissions and increased fuel efficiency.

The W126 design team, led by Mercedes-Benz's chief designer [[Bruno Sacco]], aimed to design a more aerodynamic shape and retain the unmistakable S-Class design elements. The aerodynamic drag was reduced through lengthy wind tunnel testing and reshaping of the front end and bumper along with hiding the wipers underneath the hood/bonnet for smoother flow. Reducing the weight was accomplished by extensive use of [[High-strength low-alloy steel|high-strength low-alloy (HSLA) sheet]] and polyurethane deformable material for bumpers and side claddings. The lighter alloy material was used for the heavily revised M116/M117 V8 engines for reduced weight. Both contributed to the reduction of fuel consumption by 10% as compared to its predecessor.<ref name=S-Klasse/>

After six years of development, the W126 was introduced at the [[International Motor Show Germany#1979|IAA Frankfurt]] in September 1979.<ref name=Keesings79>{{cite journal |title=Salon van Frankfurt is aanklacht tegen politieke machthebbers |trans-title=Frankfurt Show is an indictment of political leaders |language=nl |journal=Keesings Auto Magazine |location=Antwerp, Belgium |date=15 September 1979 |volume=2 |number=17 |pages=16–18 |editor-last=Rombauts |editor-first=Walter }}</ref> At the introduction, S-Class was available in two wheelbase lengths (standard and long) and three petrol engine options with one six-cylinder inline engine and two V8 engines. The diesel engine option was introduced in September 1981 exclusively for the North American market.

At the 1981 [[International Motor Show Germany#1981|IAA Frankfurt]], the C126, a coupé version of the S-Class, was introduced with 380 SEC and 500 SEC trims initially offered. It was the first time that a coupé version was derived from an S-Class chassis. However, the styling was different between the two, making it the first time that the coupé had fully distinct styling, later evolving into [[CL-Class]]. At the same time, the "Energiekonzept" (Energy Concept) was introduced to improve the fuel efficiency of S-Class through engine revisions.

The W126 was revised in 1985 for the 1986 model year. The revised "Second Series" model range was introduced at the 1985 [[International Motor Show Germany#1985|IAA Frankfurt]] with new six-cylinder petrol and diesel engines and the V8 petrol engines enlarged to 4.2 and 5.5 litres. The 5-litre V8 was carried over. Visual changes included smoother bumpers and side claddings, revised "Gullydeckelfelge" (German for manhole-cover wheel rim) alloy wheels, and a deeper front bumper with integrated air dam.

The W126 generation was replaced by the [[Mercedes-Benz W140|W140]] in 1991.

== Styling ==
[[File:1989 Mercedes-Benz 560 SEL (V 126) sedan (23188230022).jpg|thumb|Facelift Mercedes-Benz 560 SEL (V126)]]

From 1973 to 1975, Mercedes-Benz designers worked on the successor to the [[Mercedes-Benz W116|W116]]. After several design concepts were presented, the final design for the W126 was approved and frozen in 1976. The design work for the coupé began immediately after the approval and was finalised in 1977.<ref>{{cite web |url=http://home.concepts.nl/~vlimmere/the_facts.HTM |title=The Facts |access-date=2 May 2013 |url-status=dead |archive-url=https://archive.today/20130616071432/http://home.concepts.nl/~vlimmere/the_facts.HTM |archive-date=16 June 2013}}</ref> Design patents were first filed on 3 March 1977 and later on 6 September 1977 at the United States Patent Office.<ref>{{cite web|url=https://patents.google.com/patent/USD258425 |work=Google Patents |title=USD258425S United States |access-date=1 December 2020}}</ref>

Compared to its predecessor, the W116, the W126 featured improved aerodynamics with a [[drag coefficient]] of Cd 0.36 for the sedan/saloon and 0.34 for the coupés.<ref name="W126history"/>

== Models ==
[[File:1984 Mercedes-Benz 380 SE (W 126) sedan (2015-08-07) 02.jpg|thumb|right|Pre-facelift Mercedes-Benz W126 380 SE (standard wheelbase version)]]
[[File:1989 Mercedes-Benz 560 SEL (V 126) sedan (23213887641).jpg|right|thumb|Facelift Mercedes-Benz 560 SEL V126 (long-wheelbase version)]]
[[File:Mercedes Benz 500 SEC 1983 (15003999886).jpg|thumb|right|Pre-facelift Mercedes-Benz C126 SEC (coupe)]]
[[File:1984 Mercedes-Benz 500 SEC (14763026989) (cropped).jpg|thumb|right|Pre-facelift Mercedes-Benz C126 SEC (coupe)]]
[[File:Mercedes-Benz 500 SEC (C 126, Facelift) – Frontansicht, 10. August 2013, Hilden.jpg|thumb|right|Facelift Mercedes-Benz C126 SEC (coupe)]]
[[File:1987 Mercedes-Benz 560 SEC (C126) (4986758107).jpg|thumb|right|Facelift Mercedes-Benz C126 SEC (coupe)]]

The pre-facelift model range (1979–1985 for sedan/saloon and 1982–1985 for coupé) included the 280 S/SE/SEL, 300 SD (North American market only), 380 SE/SEL/SEC, and 500 SE/SEL/SEC. The revised second series (1986–1991) with petrol engines included 260 SE, 300 SE/SEL, 420 SE/SEL/SEC, 500 SE/SEL/SEC, and 560 SE/SEL/SEC. The updated version of diesel model, 300 SDL, was exclusive to the North American market (the first time the S-Class with diesel engine was offered in long wheelbase) and then the 350 SD/SDL (the first diesel S-Class to be available in both wheelbase lengths).

=== Safety ===
[[File:500 SEL W126 1.jpg|thumb|right|Late model W126 with Airbag, leather seats, and Burlwood interior wood trim. Left hand Drive.]]

* Use of [[High-strength low-alloy steel|high-strength low-alloy (HSLA) sheet]] in its construction to reduce the weight without compromising the structural strength and integrity.
* [[Anti-lock braking system]] (ABS) (first appeared in its predecessor, the W116). It was an optional extra for all models and engines until late December of 1984 when it was made standard for the V8 models.<ref>380 SE / W 126 E 38, 1980 - 1985|https://mercedes-benz-publicarchive.com/marsClassic/en/instance/ko/380-SE--W-126-E-38-1980---1985.xhtml?oid=4855</ref><ref>500 SEL / V 126 E 50, 1980 - 1985 Chassis and Drivetrain|https://mercedes-benz-publicarchive.com/marsClassic/en/instance/ko/500-SEL--V-126-E-50-1980---1985.xhtml?oid=4846</ref> [[Anti-lock braking system]] (ABS) became standard equipment in September of 1986 for the 260 SE,<ref>260 SE / W 126 E 26, 1985 - 1991 Chassis and Drivetrain|https://mercedes-benz-publicarchive.com/marsClassic/en/instance/ko/260-SE--W-126-E-26-1985---1991.xhtml?oid=4993</ref> 300 SE<ref>300 SE / W 126 E 30, 1985 - 1991 Chassis and Drivetrain|https://mercedes-benz-publicarchive.com/marsClassic/en/instance/ko/300-SE--W-126-E-30-1985---1991.xhtml?oid=4981</ref> and 300 SEL.<ref>300 SEL / V 126 E 30, 1985 - 1991 Chassis and Drivetrain|https://mercedes-benz-publicarchive.com/marsClassic/en/instance/ko/300-SEL--V-126-E-30-1985---1991.xhtml?oid=4982</ref> [[Anti-lock braking system]] (ABS) was standard in the U.S spec 300 SDL,<ref>300 SDL Turbodiesel / V 126 D 30 A, 1985 - 1987 Chassis and Drivetrain|https://mercedes-benz-publicarchive.com/marsClassic/en/instance/ko/300-SDL-Turbodiesel--V-126-D-30-A-1985---1987.xhtml?oid=4991</ref> 350 SD<ref>350 SD Turbodiesel / W 126 D 35 A, 1990 - 1991 Chassis and Drivetrain|https://mercedes-benz-publicarchive.com/marsClassic/en/instance/ko/350-SD-Turbodiesel--W-126-D-35-A-1990---1991.xhtml?oid=4987</ref> and 350 SDL.<ref>350 SDL Turbodiesel / V 126 D 35 A, 1990 - 1991 Chassis and Drivetrain|https://mercedes-benz-publicarchive.com/marsClassic/en/instance/ko/350-SDL-Turbodiesel--V-126-D-35-A-1990---1991.xhtml?oid=4990</ref> 
* [[Seat belt#Pretensioners and webclamps|Seat Belt Pretensioners]] enabled all seat belts (with exception of rear centre shoulder belt on sedan/saloon) to tighten when the car sensed conditions that could lead to an accident such as sudden, forceful braking or sudden deceleration during the collision.<ref name=W126history>{{cite web|url=http://www.geocities.com/MotorCity/Flats/2188/ |title=Celebrating the 25th anniversary of W126/V126/C126 S-Class (1979–1991) |first=Ian |last= Dunross |access-date=15 May 2007 |archive-url=https://web.archive.org/web/20070806112653/http://www.geocities.com/MotorCity/Flats/2188/ |archive-date=6 August 2007}}</ref>
* [[Crumple zones]] front and rear which absorbed impact energies, reducing passenger injury.
* Fluted taillamps, the design pioneered on the [[Mercedes-Benz R107 and C107|R107/C107]], was carried over. The fluted design maintains the visibility of taillamps when the dirt accumulates on the outer edges.
* [[Airbag|Airbags]] The driver's side airbag was introduced in 1981 as an extra-cost option for all models and engines. The consumers could either choose driver's airbag only or driver's and passenger's airbags. For the US market, the driver's side airbag became standard for the 1985 model year<ref>1985 Mercedes-Benz 500 SEC | Retro Review Show 406 | Original Airdate 10-16-1984|https://www.youtube.com/watch?v=ZIBS0ep420Q</ref><ref>Road & Track, March of 1985|https://www.germancarforum.com/threads/ams-test-40-year-celebration-of-mercedes-500sel-w126.60145/post-1468627</ref> onwards. From September 1987 on, the passenger's side front airbag were added as extra-cost option for the 1988 model year. The passenger's front airbag was an extra cost option until 1989 when it became standard for models with V8 engines only and 1991 for the rest of model range.
* [[Traction control system]] (TCS), also known as [[Acceleration Slip Regulation]] (ASR), to prevent [[wheelspin]] (a Mercedes-Benz first). This feature was available on European models only from 1989 and 1991 and on North American models (560 SEL and 560 SEC) for 1991 only.
* A [[third brakelight|third brake lamp]] in the centre of rear windscreen was federally mandated in the United States from 1986 model year on. In some markets, it was offered as standard or extra-cost option.

=== Comfort and convenience ===
[[File:1981 Mercedes Benz W126 Interior Blue.jpg|thumb|Early model W126 without airbag, MB-Tex seats, and Zebrano interior wood trim. Right Hand Drive.]]

* [[Automotive lighting#Convenience lights|Courtesy lights]] on the underside of the doors, to enable the occupant to see the ground when exiting the vehicle at night.
* Rear reading lamps were fitted to the C-pillar enabling rear passengers to read or work at night without distracting the driver. Extra cost options for the rear seat passengers were: individually adjusted seat heaters (never offered in coupé models during its entire production run); bench seat that can move forward and back electrically by 10&nbsp;cm (long wheelbase models only); foot rests; from 1987 on, rear windscreen window shades that are electrically raised and lowered by switch on centre console; and the back of front seats are contoured as to give more legroom. 
* From 1979 to 1984, the driver and front passenger seat heaters were separate extra-cost options. From 1985 to 1991, both driver and front passenger seat heaters were offered as a single extra-cost option.
* Beginning with 1985 model year, the rear individual seats and centre console as appeared in coupé model could be fitted to the long wheelbase models if the owner desires, giving the car a [[2+2 (car body style)|2+2]] seating format. The individual seat is electrically adjustable by moving forward and back only.
* An optional fully automatic [[climate control]] system that used an interior temperature sensor to more accurately climatise the cabin. This sensor was mounted overhead (near the sunroof switch) so that when the roof was open, the sensor would detect cool air-flow and call upon the system to adjust heat flow accordingly.
* Exterior [[temperature sensor]] with [[LCD]] display set in main instrument console below the speedometer to inform the driver of exterior conditions. This was delineated in Fahrenheit for US-market cars and in Celsius for the rest of the world.
* Due to the B-pillar moving further back in the coupé models with longer doors, Mercedes-Benz developed the world's first seat belt presenters. When the doors are closed and the motor started, the presenters extend the shoulder anchor points forward to the driver and front passenger by about 30&nbsp;cm. This facilitates easier reach and grab of seat belts. Once the seat belts are anchored or after 30 seconds, the presenters descended back into the B-pillar.
* W126 premiered the power seat control, a first for Mercedes-Benz. Instead of placing the toggle or button switches with same shapes in the hard to reach or see areas, Mercedes-Benz developed the haptic switches in shape of a seat: one switch resembling the seat back for adjusting the seat back; another switch resembling the seat for moving the seat forward and back as well as raising and lowering. The two memory function buttons allow the front occupants to set and select their preferred positions accordingly. After the 17-year patent expired, this design was widely copied by other manufacturers in the late 1990s. Another first for Mercedes-Benz is an electrically adjustable steering column that extends and contracts by toggle switch underneath the steering column. The steering column position can be stored in the driver's side memory function along with the preferred seat position.
* W126 was the first car from Mercedes-Benz to have the theft deterrent system as an option installed at the factory. EDW (Einbruch-Diebstahl-Warnanlage, break-in theft alarm system) can emit an alarm sound and immobilise several components (radio, brakes, ignition lock, and a few others) if the car was being towed away or if any of hood/bonnet, trunk/boot, doors were forcibly opened. From 1984 on for the models with central locking system, the owner can turn the front door lock further to bolt the doors as to make them very difficult to be forcibly opened. The owner can order the separate bolt system for the trunk/bolt, making it equally difficult to pry the trunk/boot open. They require a special key with red dot.

=== Drivetrain technologies ===
The four-speed [[Mercedes-Benz 4G-Tronic transmission|4G-Tronic transmission]] had a new topographical sensor that improved the drivability by monitoring the vehicle's position (flat surface, incline, or decline) and the position of throttle pedal. This prevents the unintended acceleration when coasting downhill without the frequent braking to maintain the speed. The Second Series has a "hill-hold" feature that prevents the vehicle from rolling back suddenly when disengaging the brake and engaging the throttle pedals at the steep incline. The transmission in European models has a S/W switch to allow the start in either first (Standard) or second (Winter) gear respectively. The "Second Series" changed the S/W to S/E for Economy. The topographical sensor also offers a better driving experience with cruise control by adjusting the throttle smoothly and automatically without sudden lurching or decelerating when maintaining the desired speed.

The W126 carried forward the [[self-levelling suspension|self-leveling]] [[hydropneumatic suspension]] of the W116 450 SEL 6.9 model. Like the W116 and W123, the rear-wheel hydropneumatic suspension system was offered in W126 as an option. The updated version was called HPF II (short for ''Hydropneumatische Federung'') was available from 1981 to 1985 (on the 380 SEL and 500 SEL) and very briefly on the 500 SE in 1985. The self-levelling technology responds to changes in weight distribution (passengers, luggage, fuel, etc.) and was therefore less applicable in shorter wheelbase models.

For the "Second Series" (1986-1991), the hydropneumatic suspension was heavily redesigned and named HPF III. The HPF III automatically lowers the chassis by 24&nbsp;mm when the vehicle is travelled at least 120&nbsp;km/h for improved aerodynamic flow and better high speed stability. The system adjusts the damping rate from soft to hard based on speed and road condition for extra comfort and better drivability. Additionally, the driver can select to raise the car by 35&nbsp;mm if travelling over coarse-surfaced road (only up to 80&nbsp;km/h). From 1986 to 1990, the HPF III option was available in 420 SEL, 500 SEL, 560 SE, and 560 SEL. For the final year of production, HPF III was available in longer wheelbase only (420 SEL, 500 SEL, and 560 SEL). Due to its complexity and tendency to fail catastrophically, HPF III was very difficult to service and was often, at the owner's request, removed and replaced with coil springs and shock absorbers from models without hydropneumatic suspension system.<ref>{{cite web|url=https://5komma6.mercedes-benz-passion.com/der-w126-damals/innovationen/hydropneumatische-federung-hpf/ |work=MBpassion |access-date=30 December 2019 |language=de |title=Hydropneumatische Federung (HPF)}}</ref>

At the 1983 [[International Motor Show Germany#1983|IAA]], Mercedes-Benz introduced ''Reiserechner'' ("Trip calculator"), its first [[trip computer]] option, in the W126 for the 1984 model year.<ref>{{cite web|url=https://5komma6.mercedes-benz-passion.com/der-w126-damals/innovationen/reiserechner/ |language=de |title=Reiserechner |work=MBpassion |access-date=30 December 2019}}</ref> The trip computer has a rectangular control panel on the centre console between the power window switches and the round information panel in the instrument clusters. The control panel features a series of buttons which feature haptic touch to allow the driver to feel his way around the control buttons without taking his eyes off the road. A panel occupies the gauge cluster formerly used by tachometer, which moved to the left gauge cluster, sharing with oil, fuel, and temperature gauges. The information panel contains a large horizontal LCD display in the middle. The option was dropped from the W126 a few years later due to the complexity of configuring the trip computer, requiring an accompanying 18-page instruction handbook to understand its operation, and due to the frequent failure of its control panel buttons.{{Citation needed|date=April 2024}}

== Engines ==

'''First Series (1979–1985)'''

At the introduction in September 1979, the 2.8-litre [[DOHC]] six-cylinder inline [[Mercedes-Benz M110 engine|M110]] engine from the 280 S/SE/SEL was carried over from the W116. The revised [[Mercedes-Benz M116 engine|M116]]/[[Mercedes-Benz M117 engine|M117]] V8 engines had a significant innovation: an aluminium block without iron sleeves as found in the competitors’ engines. Mercedes-Benz developed a special [[silicon]] coating as to harden the cylinder liners against excessive wear and tear. The V8 engines were offered in two sizes: 3.8 litres (M116) and 5 litres (M117). The M116 V8 engine had a single timing chain while the M117 V8 engine had double timing chains. The frequent mechanical failure of the single timing chain in the M116 was addressed in 1982 by switching to double timing chains from the M117 V8 engine.

The smaller of the two V8 engines was initially the only one offered in the US market, to help meet [[Corporate average fuel economy|Corporate Average Fuel Economy (CAFE)]] requirements. The 380 SEL received a poor customer perception in the United States as being severely underpowered and due to mechanical issues with the single timing chain. The 380 SEL for the US market took 11 seconds to reach {{convert|60|mi/h|km/h|abbr=on}} from standstill and had top speed of {{convert|117|mi/h|km/h|abbr=on}}.<ref name=HBG>{{cite web|url=https://www.hagerty.com/media/car-profiles/definitive-1979-92-mercedes-benz-w126-s-class-buyers-guide/|title=Your definitive 1979-92 Mercedes-Benz W126 S-Class Buyer's Guide |first=Chris |last=Chin |publisher=Hagerty Group LLC |date=24 October 2019 |access-date=9 September 2020}}</ref><ref name=US380SEL>{{cite web|url=https://www.automobile-catalog.com/car/1982/1476290/mercedes-benz_380_sel.html |title=1982 Mercedes-Benz 380 SEL (aut. 4) (model since mid-year 1981 for North America U.S.) car specifications & performance data review |work=Automobile Catalog |access-date=9 September 2020}}</ref> The severe performance shortcoming of W126 with V8 engine was addressed by introducing more powerful 500SEL/SEC in 1984.

The S-Class coupé was fitted with V8 engines only for the first time.[[File:1983 Mercedes-Benz 300SD US.jpg|thumb|1983 Mercedes 300SD with the OM617 Turbodiesel engine]]The 3-litre five-cylinder inline [[Mercedes-Benz OM617 engine|OM617]] diesel engine was carried over from the [[Mercedes-Benz W116|W116]] with the same performance. The diesel engines were again never offered in the markets outside United States and Canada. This discrepancy was not addressed until 1994 when the [[Mercedes-Benz W140|W140]] S 350 Turbodiesel was introduced in Europe.

In 1981, Mercedes-Benz introduced the ''Energiekonzept'' ("Energy Concept") programme in reducing the fuel consumption. This programme revised the combustion chambers and piston heads with lower compression ratio in the V8 engines. This revision caused a further drop in engine performance.

'''Second Series (1986–1991)'''

For the second series introduced in September 1985, the engine range was extensively revised with new six-cylinder inline engines and enlarged V8 engines. Only the 5-litre M117 V8 was carried over from the first series, expanding the V8 engine range to three.

The revised engine range focused more on reducing pollution and fuel consumption even further. For the first time, the customers outside US and Canadian markets could choose the models with or without catalysators. The models without [[Catalytic converter|catalysators]] can be retrofitted with catalysators at later date if the customers choose to: this retrofit method is called RÜF (Rückrüstfahrzeug — loosely translated as retrofit vehicle). The RÜF models had a mechanical switch in the engine bay to be operated by owners for running on lead or lead-free fuels, a necessary feature for driving outside Germany or in areas within Germany where the lead-free fuel wasn't widespread yet. In 1990, all engines were fitted with catalysators only and the mechanical switch eliminated.

The new six-cylinder inline [[Mercedes-Benz M103 engine|M103]] engine had a single overhead camshaft and electronic-mechanical fuel injection and was available in two sizes: 2.6 and 3 litres. The carburetted engine fitted to the 280 S was eliminated, marking the end of carburetted engines for the S-Class, and replaced with fuel-injected engines for the 260 SE and 300 SE/SEL.

For the V8 engines, the M116 was bored out to 4.2 litres from 3.8 litres for the 420 SE/SEL/SEC while the 5-litre V8 for 500 SE/SEL/SEC was carried over. A new 5.5 litre engine was introduced for the 560 SE/SEL/SEC which was accomplished by stroking the 5-litre M117 engine with a new crankshaft. The V8 engines were fitted with new electronic ignition system and [[Robert Bosch GmbH|Bosch]] [[Jetronic#KE-Jetronic (1985-1993)|KE-Jetronic]] [[Fuel injection#Multi-point injection|electronic-mechanical fuel injection system]], first appeared in [[Mercedes-Benz W201|W201]] 190E. The revised V8 engines except 5-litre version had slight performance increase.

The most powerful engine ever fitted to the W126 S-Class was a 5.5-litre V8, putting out 221&nbsp;kW (300 PS, 296&nbsp;bhp). This engine, classified as ECE-Variante (German name), has a higher [[compression ratio]] of 10:1 and cannot be retrofitted with a catalysator at a later date. In September 1986, the ECE-Variante was superseded by the RÜF-Variante, which retains the same horsepower figure without catalysator and lower figure if retrofitted with a catalysator at a later date. In 1990, the power of the 560 SEL was reduced to {{convert|200|kW|PS bhp|abbr=on|0}}.

[[File:W126 1986 Mercedes 300SDL.jpg | thumb | 1986 Mercedes 300SDL with the OM603 Turbodiesel engine]]

For the US and Canadian markets, a new 3-litre six-cylinder inline [[Mercedes-Benz OM603 engine|OM603]] diesel engine was introduced, replacing the five-cylinder engine with same displacement. It was the first six-cylinder passenger diesel engine by Mercedes-Benz. This new engine was available in the long wheelbase version only, 300 SDL, for the first time. For California, the diesel engines were fitted with a [[diesel particulate filter]], a world's first for a passenger car. The new engine had an ill-gotten reputation for higher percentage of aluminium cylinder head failure due to poor placement of the diesel particulate filter and due to the erosion of the head gasket, allowing cooling fluid to seep into the cylinders. However, they failed to perform as designed and were removed from the engines. For 1988, the engine was revised to correct the issues and move the particulate filter further away from the engine.

In 1990, the same engine was bored out to 3.5 litres as to compensate for reduced performance due to stricter emission regulations. The bored out 3.5-litre version did not have any of aforementioned issues other than some units experiencing the unexplained erosion of head gasket. The 3.5-litre version was available in both standard and long wheelbases (350 SD and 350 SDL) for the first time in the S-Class.

== Transmissions ==

'''First Series (1979–1985)'''

The automatic transmission [[Mercedes-Benz 4G-Tronic transmission|4G-Tronic]] had four speeds with direct drive in the fourth gear for the entire run from 1979 to 1991.

The 280 S/SE/SEL had 4-speed manual transmission as standard with 5-speed manual and 4-speed automatic transmissions as extra-cost options. Manual transmission was not fitted to the V8 engines.

U.S. models, including the 300 SD Turbodiesel, had automatic transmission as sole transmission choice.

'''Second Series (1985–1991)'''

From 1986 onward, the automatic transmission [[Mercedes-Benz 4G-Tronic transmission|4G-Tronic]] was revised to include the option of selecting S (Standard) and E (Economy) shifting points.

The models 260 SE and 300 SE/SEL were fitted with the standard 5-speed manual and optional extra-cost 4-speed automatic transmissions. For one year from September 1986 to June 1987, the extra cost automatic transmission option wasn't offered for the 260 SE and 300 SE.{{Citation needed|date=May 2025}} Manual transmission was not fitted to the V8 engines.

U.S. models had the automatic transmission as the sole transmission choice.

== U.S. grey market ==
[[File:Mercedes-Benz 500SE.jpg|thumb|Grey-market Mercedes-Benz 500 SE]]

When the W126 was introduced in the United States in September 1980, Mercedes-Benz only offered the smaller 3.8-litre V8 engine to avoid the gas guzzler penalty under [[Corporate average fuel economy|Corporate Average Fuel Economy (CAFE)]] regulations. However, American consumers found the 380 SEL severely underpowered with slow acceleration (0–60&nbsp;mph in 11 seconds) and a lower top speed of {{convert|117|mi/h|km/h|abbr=on}}.

As the fear of oil crisis waned in 1982, American consumers demanded the more powerful S-Class models, and [[Grey import vehicle#United States|grey importers]] brought the S-Class with 5-litre V8 engines to the United States and modified them to meet US [[Federal Motor Vehicle Safety Standards|FMVSS]] and [[United States Environmental Protection Agency|EPA]] regulations. The 280 S/SE/SEL with smaller six-cylinder inline engines were also imported, offering significant savings over the V8 models. The W126 was a major part of this parallel market, with 22,000 imported in a segment that hit 66,900 cars in 1985, the biggest year for grey imports.<ref>{{cite web|url=https://www.gao.gov/assets/150/145479.pdf|page=2|title=Tax Administration Gas Guzzler Tax Compliance Can Be Increased|publisher=United States General Accounting Office| date=16 July 1987|access-date=9 September 2020}}</ref>

Consequently, Mercedes-Benz added the 500 SEL/500 SEC to the American model range for 1984 model year to counter the grey imports while the 3.8-litre V8 engine remained in 380 SE (standard wheelbase only) and 380 SL.<ref>{{cite web|url=http://www.peachparts.com/shopforum/diesel-discussion/243314-high-quality-pictures-1984-brochure.html |title=Mercedes-Benz for 1984 |work=Mercedes-Benz USA |access-date=1 December 2020}}</ref>

In 1988, an intense lobbying effort by Mercedes-Benz and other foreign manufacturers led U.S. Congress to eliminate this consumer option and revise the rules for registered importers.<ref>{{cite web|url=https://www.latimes.com/archives/la-xpm-1986-07-11-vw-19912-story.html |last=Dean |first=Paul |title=Wheeling-Dealing Gray Market Hits the Skids Bad Publicity, Corporate Action, Legislation Put Brakes on Car Conversions |work=Los Angeles Times |date=11 July 1986 |access-date=14 November 2019}}</ref>

== Special variants ==
[[File:1989 Mercedes-Benz 560 SEC 5.6 AMG 'Wide Body'.jpg|thumb|1989 Mercedes-Benz 560 SEC 5.6 AMG 'Wide Body']]
* [[File:Mercedes-Benz W126 Sechstürer vr.jpg|thumb|right|Mercedes-Benz W126 six-door stretch limousine]]Although it had not yet merged with Mercedes-Benz, "pre-merger" [[Mercedes-AMG|AMG]] offered body kits for all W126 models, as well as a "wide body" kit for the coupé. The "wide body" cars were fitted with distinctive AMG-designed front and rear fenders and door panels that allowed much wider wheels and tires to be fitted. AMG also offered engine modifications with displacements of 5, 5.5, and 6 litres. The most famous and rarest was the [[DOHC]] 6-litre engine, based on the original 117.968 engine. Some of options offered were [[Torsen differential|Gleason Torsen]] differential in various ratios, [[manual transmission]] (extremely rare), and various TV/radio consoles.
* Trasco Bremen offered a [[stretch limousine]] version called the "1000 SEL".<ref>{{cite web|title=Transco Bremen Stretch Limousine 1000SEL|url=http://www.1000sel.com/index.php/trasco/mercedes-w126-sel-stretch#:~:text=A%20Trasco%201000SEL%2012%20in%20a%20more%20discrete,Trasco%201000SEL12%20Mercedes-Benz%2C%20though%20of%20a%20different%20flavour |publisher=1000SEL.com |access-date=25 September 2020}}</ref>
* A variety of coachbuilders offered convertibles based on the SEC (coupé) model. Caruna of Switzerland also offered a full four-door convertible based on the SEL (but using the SE's shorter rear doors). One of these (a blue one) still belongs to the Dutch royal family, who use it at their resort in [[Porto Ercole]], Italy.<ref name=Caruna1>{{cite web|url=http://www.autoblog.nl/archive/2009/06/16/juultje-had-smaak-mercedes-benz-380-sel-caruna |date=16 June 2009 |title=Juultje had smaak: Mercedes-Benz 380 SEL Caruna |trans-title=Juultje had taste |last=Karssen |first=Wouter |publisher=Autoblog (Netherlands) |language=nl |access-date=8 August 2014}}</ref>
*A coachbuilder, Caro International, built an estate/station wagon version of W126 S-Class called 560 TEL.<ref>{{cite web|url=https://www.carscoops.com/2020/05/this-1990-mercedes-benz-560-tel-is-the-s-class-wagon-stuttgart-would-not-build/ |title=This 1990 Mercedes-Benz 560 TEL Is The S-Class Wagon Stuttgart Would Not Build |first=Dan |last=Mihalascu |work=Car Scoops |date=5 May 2020}}</ref>
* [[Mercedes Guardian|Guard]], specially modified W126 S-Class models were produced for the transport of dignitaries and world leaders. Among the modifications made included a wheelbase stretch, [[bulletproof glass]], and armored body panels.

== Racing ==
Two [[Mercedes-AMG|AMG]]-modified 500 SEC cars raced at the 1989 [[24 Hours of Spa]]. Both cars failed to finish, with one suffering gearbox issues, while the other had issues with the rear axle.<ref>{{cite web|url=http://www.racingsportscars.com/type/archive/Mercedes-Benz/500%20SEC.html?cat=4 |title=Mercedes-Benz 500SEC – Complete Archive |publisher=Racing Sports Cars |access-date=2011-10-16}}</ref>

== Awards ==
* The 300 SD received the 1981 [[Motor Trend Car of the Year|Motor Trend Import Car of the Year]].
* The 380 SE was the ''[[Wheels Magazine]]'' [[Wheels Car of the Year|Car of the Year]] in 1981.<ref name=wheelsmag>{{cite web|url=http://www.wheelsmag.com.au/wheels/site/articleIDs/C40CA2CB6C8577F1CA257285001E7302?open&template=domWheels |title=Wheels' COTY the real McCoy |last=Gable |first=Chris |access-date=15 May 2007 |date=12 April 2006 |url-status=dead |archive-url=https://web.archive.org/web/20070927115318/http://www.wheelsmag.com.au/wheels/site/articleIDs/C40CA2CB6C8577F1CA257285001E7302?open&template=domWheels |archive-date=27 September 2007}}</ref>
* The W126 was awarded the [[Insurance Institute for Highway Safety|U.S. Highway Loss Data Institute]] "Safest Passenger Car of the Year" in 1988 and 1989.<ref name=W126history/>{{unreliable source?|date=June 2020}}
* The W126 was the third-ranked luxury vehicle in J.D. Power's 1990 Initial Quality Survey (IQS).<ref>Lexus No. 1 in New-Car Quality Survey, ''[[The Los Angeles Times]]'', 4 July 1990 (Versus an average of 140 problems per 100 cars, the S-Class averaged 74.5, behind only the Mercedes E-Class and Lexus LS)</ref>
* From 1987 to 1990, Mercedes received the highest customer ratings in the [[J.D. Power and Associates|J.D. Power]] Sales Satisfaction Index.<ref>Sanchez, Jesus. Mercedes Still Ranks No. 1 in Poll of New Car Buyers. ''[[The Los Angeles Times]]'', 8 August 1990</ref>

== Legacy ==
The W126 series was the highest volume S-Class on record in terms of production.

A limited number of W126 continued to be produced in South Africa until 1993(?), two years after the introduction of W140 S-Class. No figures were given for South African production. Nelson Mandela was given a commemorative model, a red 1990 500 SE.<ref>{{cite web|url=https://www.carmag.co.za/news/we-check-out-nelson-mandelas-special-w126-mercedes-benz-500se/ |title=We check out Nelson Mandela's special W126 Mercedes-Benz 500 SE... |date=24 April 2020 |first=Wilhelm |last=Lutjeharms |work=Carmags (South Africa)}}</ref><ref>{{cite web|url=http://jalopnik.com/the-story-of-the-special-mercedes-s-class-made-for-nels-1478020750 |title=The Story Of The Special Mercedes S-Class Made For Nelson Mandela |last=Torchinsky |first=Jason |date=6 December 2013 |work=Jalopnik}}</ref>

Three armoured 560 SEL ordered by Saddam Hussein had a series of pipes that shot flames out of the sides.<ref>{{cite journal |last=Apuzzo |first=Matt |date=2006-05-21 |title=US agents seize 'Saddam Hussein's car' |url=http://mg.co.za/article/2006-05-21-us-agents-seize-saddam-husseins-car |journal=[[Mail & Guardian]] |location=Johannesburg, South Africa |publisher=M & G Media |access-date=2014-10-30}}</ref>

==Technical data==
{| class="wikitable" style="text-align:center; font-size:0.85em;"
|+ First Series, 1979-1985 <ref>{{Cite web |title=126 series S-Class Saloons, 1979 - 1985 |url=https://mercedes-benz-archive.com/marsClassic/en/instance/ko/126-series-S-Class-Saloons-1979---1985.xhtml?oid=4845 |access-date=2025-01-29 |website=marsClassic |language=en}}</ref>
|-
!Model!!Chassis!!Years!!Configuration!!Displacement!!Fuel Delivery!!Power!!Torque!!Curb Weight (kg)!!0–100&nbsp;km/h (0-62&nbsp;mph)!!Top Speed (km/h)!!Fuel Consumption!!Units
|-
! colspan="13" style="background:#E8E8E8"| ''Petrol Engines''
|-
|280 S
|W126.021
|rowspan="3"|09/1979 – 08/1985
|([[Mercedes-Benz M110 engine|M 110.924]]) Inline 6
|rowspan="3"|2746 cc
|Two-stage twin-barrel downdraught carburettor ({{ill|Solex 4A1|de}})
|{{cvt|115|kW|PS bhp|0}}
|{{cvt|223|Nm|lbft|0}}
|1560
|11 seconds
|{{Convert|200|km/h|0|abbr=on}}
|{{convert|15.1|L/100 km|mpgUS|abbr=on}}
|42,996
|-
|280 SE
|W126.022
|rowspan="2"|([[Mercedes-Benz M110 engine|M 110.989]]) Inline 6
|rowspan="2"|Mechanical continuous [[multi-point injection]] ([[Bosch K-Jetronic]])
|rowspan="2"|{{cvt|136|kW|PS bhp|0}}
|rowspan="2"|{{cvt|240|Nm|lbft|0}}
|1560
|rowspan="2"|10 seconds
|rowspan="2"|{{Convert|210|km/h|0|abbr=on}}
|rowspan="2"|{{convert|15.6|L/100 km|mpgUS|abbr=on}}
|133,955
|-
|280 SEL
|W126.023
|1590
|20,655
|-
|rowspan="2"|380 SE
|rowspan="2"|W126.032
|09/1979 – 08/1981
|rowspan="5"|([[Mercedes-Benz M116 engine|M116.963]]) V8
|rowspan="5"|3818 cc
|rowspan="5"|Mechanical continuous multi-point injection (Bosch K-Jetronic)
|{{cvt|160|kW|PS bhp|0}}
|{{cvt|305|Nm|lbft|0}}
|rowspan="2"|1595
|9.8 seconds
|rowspan="2"|{{Convert|210|km/h|0|abbr=on}}
|rowspan="5"|{{convert|17.5|L/100 km|mpgUS|abbr=on}}
|rowspan="2"|58,239
|-
|09/1981 – 08/1985
|{{cvt|150|kW|PS bhp|0}}
|{{cvt|315|Nm|lbft|0}}
|9.6 seconds
|-
|rowspan="2"|380 SEL
|rowspan="2"|W126.033
|09/1979 – 08/1981
|{{cvt|160|kW|PS bhp|0}}
|{{cvt|305|Nm|lbft|0}}
|rowspan="2"|1625
|9.8 seconds
|{{Convert|215|km/h|0|abbr=on}}
|rowspan="2"|27,014
|-
|09/1981 – 08/1985
|{{cvt|150|kW|PS bhp|0}}
|{{cvt|315|Nm|lbft|0}}
|9.6 seconds
|{{Convert|205|km/h|0|abbr=on}}
|-
|380 SEC
|W126.043
|09/1981 – 08/1985
|{{cvt|150|kW|PS bhp|0}}
|{{cvt|315|Nm|lbft|0}}
|1585
|9.6 seconds
|{{Convert|210|km/h|0|abbr=on}}
|11,267
|-
|rowspan="2"|500 SE
|rowspan="2"|W126.036
|09/1979 – 08/1981
|rowspan="5"|([[Mercedes-Benz M117 engine|M117.963]]) V8
|rowspan="5"|4973 cc
|rowspan="5"|Mechanical continuous multi-point injection (Bosch K-Jetronic)
|{{cvt|177|kW|PS bhp|0}}
|{{cvt|402|Nm|lbft|0}}
|rowspan="2"|1620
|8.1 seconds
|{{Convert|210|km/h|0|abbr=on}}
|rowspan="5"|{{convert|18.5|L/100 km|mpgUS|abbr=on}}
|rowspan="2"|33,418 (1979 – 1991)
|-
|09/1981 – 08/1985
|{{cvt|170|kW|PS bhp|0}}
|{{cvt|405|Nm|lbft|0}}
|8.0 seconds
|{{Convert|210|km/h|0|abbr=on}}
|-
|rowspan="2"|500 SEL
|rowspan="2"|W126.037
|09/1979 – 08/1981
|{{cvt|177|kW|PS bhp|0}}
|{{cvt|402|Nm|lbft|0}}
|rowspan="2"|1650
|8.1 seconds
|{{Convert|215|km/h|0|abbr=on}}
|rowspan="2"|72,733 (1979 – 1991)
|-
|09/1981 – 08/1985
|{{cvt|170|kW|PS bhp|0}}
|{{cvt|405|Nm|lbft|0}}
|8.0 seconds
|{{Convert|205|km/h|0|abbr=on}}
|-
|500 SEC
|W126.044
|09/1981 – 08/1985
|{{cvt|170|kW|PS bhp|0}}
|{{cvt|405|Nm|lbft|0}}
|1610
|8.0 seconds
|{{Convert|210|km/h|0|abbr=on}}
|30,184 (1981 - 1991)
|-
! colspan="13" style="background:#E8E8E8"| ''Diesel Engines (US, Canada, and Japan Only)''
|-
|rowspan="2"|300 SD
|rowspan="2"|W126.120
|09/1979 – 10/1982
|rowspan="2"|([[Mercedes-Benz OM617 engine|OM 617.951]]) Inline 5
|rowspan="2"|2998 cc
|rowspan="2"|Precombustion chamber injection<br />(Bosch five-piston inline injection pump)
|{{cvt|89|kW|PS bhp|0}}
|{{cvt|250|Nm|lbft|0}}
|rowspan="2"|1620
|rowspan="2"|15.2 seconds
|rowspan="2"|{{Convert|175|km/h|0|abbr=on}}
|rowspan="2"|{{convert|12.4|L/100 km|mpgUS|abbr=on}}
|rowspan="2"|78,725
|-
|10/1982 – 08/1985
|{{cvt|92|kW|PS bhp|0}}
|{{cvt|250|Nm|lbft|0}}
|}

{| class="wikitable" style="text-align:center; font-size:0.85em;"
|+ Second Series, 1986-1991 <ref>{{Cite web |title=126 series S-Class Saloons, 1985 - 1992 |url=https://mercedes-benz-archive.com/marsClassic/en/instance/ko/126-series-S-Class-Saloons-1985---1992.xhtml?oid=4979 |access-date=2025-01-29 |website=marsClassic |language=en}}</ref>
|-
!Model!!Chassis!!Years!!Configuration!!Displacement!!Fuel Delivery!!Power!!Torque!!Curb Weight (kg)!!0–100&nbsp;km/h (0-62&nbsp;mph)!!Top Speed (km/h)!!Fuel Consumption!!Units
|-
! colspan="13" style="background:#E8E8E8"| ''Petrol Engines (Second Series, 1986 – 1991)''
|-
|rowspan="2"|260 SE
|rowspan="2"|W126.020
|09/1985 – 02/1989
|rowspan="2"|([[Mercedes-Benz M103 engine|M 103.940]]) Inline 6
|rowspan="2"|2599 cc
|rowspan="2"|Mechanical continuous [[multi-point injection]]<br />with electronic control ([[Bosch KE-Jetronic]])
|{{cvt|124|kW|PS bhp|0}} RÜF
|{{cvt|228|Nm|lbft|0}} RÜF
|rowspan="2"|1570
|10.5 seconds
|{{Convert|205|km/h|0|abbr=on}}
|rowspan="6"|{{convert|10.3-10.7|L/100 km|mpgUS|abbr=on}}
|rowspan="2"|20,836 
|-
|09/1985 – 10/1991
|{{cvt|118|kW|PS bhp|0}} CAT
|{{cvt|220|Nm|lbft|0}} CAT
|11 seconds
|{{Convert|200|km/h|0|abbr=on}}
|-
|rowspan="2"|300 SE
|rowspan="2"|W126.024
|09/1985 – 02/1989
|rowspan="4"|([[Mercedes-Benz M103 engine|M 103.980]]) Inline 6
|rowspan="4"|2960 cc
|rowspan="4"|Mechanical continuous multi-point injection<br />with electronic control (Bosch KE-Jetronic)
|{{cvt|138|kW|PS bhp|0}} RÜF
|{{cvt|260|Nm|lbft|0}} RÜF
|rowspan="2"|1570
|9.1 seconds
|{{Convert|205|km/h|0|abbr=on}}
|rowspan="2"|105,422 
|-
|09/1985 – 10/1991
|{{cvt|132|kW|PS bhp|0}} CAT
|{{cvt|255|Nm|lbft|0}} CAT
|9.3 seconds
|{{Convert|200|km/h|0|abbr=on}}
|-
|rowspan="2"|300 SEL
|rowspan="2"|W126.025
|09/1985 – 02/1989
|{{cvt|140|kW|PS bhp|0}} RÜF
|{{cvt|260|Nm|lbft|0}} RÜF
|rowspan="2"|1590
|9.1 seconds
|{{Convert|205|km/h|0|abbr=on}}
|rowspan="2"|40,956 
|-
|09/1985 – 10/1991
|{{cvt|132|kW|PS bhp|0}} CAT
|{{cvt|255|Nm|lbft|0}} CAT
|9.3 seconds
|{{Convert|200|km/h|0|abbr=on}}
|-
|rowspan="4"|420 SE
|rowspan="4"|W126.034
|09/1985 – 05/1987
|rowspan="13"|([[Mercedes-Benz M116 engine|M 116.965]]) V8
|rowspan="13"|4196 cc
|rowspan="13"|Mechanical continuous multi-point injection<br />with electronic control (Bosch KE-Jetronic)
|{{cvt|160|kW|PS bhp|0}} RÜF
|{{cvt|330|Nm|lbft|0}} RÜF
|rowspan="4"|1620
|8.3 seconds
|{{Convert|218|km/h|0|abbr=on}}
|rowspan="13"|{{convert|11.5-11.9|L/100 km|mpgUS|abbr=on}}
|rowspan="4"|13,996 
|-
|06/1987 – 12/1989
|{{cvt|170|kW|PS bhp|0}} RÜF
|{{cvt|335|Nm|lbft|0}} RÜF 
|8.2 seconds
|{{Convert|220|km/h|0|abbr=on}}
|-
|09/1985 – 08/1987
|{{cvt|150|kW|PS bhp|0}} CAT
|{{cvt|310|Nm|lbft|0}} CAT
|8.7 seconds
|{{Convert|218|km/h|0|abbr=on}}
|-
|09/1987 – 10/1991
|{{cvt|165|kW|PS bhp|0}} CAT
|{{cvt|325|Nm|lbft|0}} CAT
|8.5 seconds
|{{Convert|220|km/h|0|abbr=on}}
|-
|rowspan="5"|420 SEL
|rowspan="5"|W126.035
|09/1985 – 05/1987
|{{cvt|160|kW|PS bhp|0}} RÜF
|{{cvt|330|Nm|lbft|0}} RÜF
|rowspan="5"|1650
|8.3 seconds
|{{Convert|218|km/h|0|abbr=on}}
|rowspan="5"|74,017 
|-
|06/1987 – 12/1989
|{{cvt|170|kW|PS bhp|0}} RÜF
|{{cvt|335|Nm|lbft|0}} RÜF 
|8.2 seconds
|{{Convert|220|km/h|0|abbr=on}}
|-
|09/1985 – 08/1987
|{{cvt|150|kW|PS bhp|0}} CAT
|{{cvt|310|Nm|lbft|0}} CAT
|8.7 seconds
|{{Convert|218|km/h|0|abbr=on}}
|-
|09/1987 – 10/1991
|{{cvt|165|kW|PS bhp|0}} CAT
|{{cvt|325|Nm|lbft|0}} CAT
|8.5 seconds
|{{Convert|220|km/h|0|abbr=on}}
|-
|09/1985 – 10/1991
|{{cvt|150|kW|PS bhp|0}} US CAT
|{{cvt|339|Nm|lbft|0}} US CAT 
|9.0 seconds (0-60 mph)
|N/A
|-
|rowspan="4"|420 SEC
|rowspan="4"|W126.046
|09/1985 – 05/1987
|{{cvt|160|kW|PS bhp|0}} RÜF
|{{cvt|330|Nm|lbft|0}} RÜF
|rowspan="4"|1640
|8.3 seconds
|{{Convert|218|km/h|0|abbr=on}}
|rowspan="4"|3,680 
|-
|06/1987 – 12/1989
|{{cvt|170|kW|PS bhp|0}} RÜF
|{{cvt|335|Nm|lbft|0}} RÜF 
|8.2 seconds
|{{Convert|220|km/h|0|abbr=on}}
|-
|09/1985 – 08/1987
|{{cvt|150|kW|PS bhp|0}} CAT
|{{cvt|310|Nm|lbft|0}} CAT
|8.7 seconds
|{{Convert|218|km/h|0|abbr=on}}
|-
|09/1987 – 10/1991
|{{cvt|165|kW|PS bhp|0}} CAT
|{{cvt|325|Nm|lbft|0}} CAT
|8.5 seconds
|{{Convert|220|km/h|0|abbr=on}}
|-
|rowspan="4"|500 SE
|rowspan="4"|W126.036
|09/1985 – 05/1987
|rowspan="12"|([[Mercedes-Benz M117 engine|M 117.965]]) V8
|rowspan="12"|4973 cc
|rowspan="12"|Mechanical continuous multi-point injection<br />with electronic control (Bosch KE-Jetronic)
|{{cvt|180|kW|PS bhp|0}} RÜF
|{{cvt|400|Nm|lbft|0}} RÜF
|rowspan="4"|1620
|7.6 seconds
|{{Convert|230|km/h|0|abbr=on}}
|rowspan="12"|{{convert|12.0-12.5|L/100 km|mpgUS|abbr=on}}
|rowspan="4"|33,418<br>(1979 – 1991) 
|-
|06/1987 – 12/1989
|{{cvt|195|kW|PS bhp|0}} RÜF
|{{cvt|405|Nm|lbft|0}} RÜF 
|7.3 seconds
|{{Convert|235|km/h|0|abbr=on}}
|-
|09/1985 – 08/1987
|{{cvt|164|kW|PS bhp|0}} CAT
|{{cvt|365|Nm|lbft|0}} CAT
|8.0 seconds
|{{Convert|220|km/h|0|abbr=on}}
|-
|09/1987 – 10/1991
|{{cvt|185|kW|PS bhp|0}} CAT
|{{cvt|390|Nm|lbft|0}} CAT
|7.5 seconds
|{{Convert|230|km/h|0|abbr=on}}
|-
|rowspan="4"|500 SEL
|rowspan="4"|W126.037
|09/1985 – 05/1987
|{{cvt|180|kW|PS bhp|0}} RÜF
|{{cvt|400|Nm|lbft|0}} RÜF
|rowspan="4"|1650
|7.6 seconds
|{{Convert|230|km/h|0|abbr=on}}
|rowspan="4"|72,733<br>(1979 – 1991) 
|-
|06/1987 – 12/1989
|{{cvt|195|kW|PS bhp|0}} RÜF
|{{cvt|405|Nm|lbft|0}} RÜF 
|7.3 seconds
|{{Convert|235|km/h|0|abbr=on}}
|-
|09/1985 – 08/1987
|{{cvt|164|kW|PS bhp|0}} CAT
|{{cvt|365|Nm|lbft|0}} CAT
|8.0 seconds
|{{Convert|220|km/h|0|abbr=on}}
|-
|09/1987 – 10/1991
|{{cvt|185|kW|PS bhp|0}} CAT
|{{cvt|390|Nm|lbft|0}} CAT
|7.5 seconds
|{{Convert|230|km/h|0|abbr=on}}
|-
|rowspan="4"|500 SEC
|rowspan="4"|W126.044
|09/1985 – 05/1987
|{{cvt|180|kW|PS bhp|0}} RÜF
|{{cvt|400|Nm|lbft|0}} RÜF
|rowspan="4"|1640
|7.6 seconds
|{{Convert|230|km/h|0|abbr=on}}
|rowspan="4"|30,184<br>(1980 – 1991) 
|-
|06/1987 – 12/1989
|{{cvt|195|kW|PS bhp|0}} RÜF
|{{cvt|405|Nm|lbft|0}} RÜF 
|7.3 seconds
|{{Convert|235|km/h|0|abbr=on}}
|-
|09/1985 – 08/1987
|{{cvt|164|kW|PS bhp|0}} CAT
|{{cvt|365|Nm|lbft|0}} CAT
|8.0 seconds
|{{cvt|220|km/h|0}}
|-
|09/1987 – 10/1991
|{{cvt|185|kW|PS bhp|0}} CAT
|{{cvt|390|Nm|lbft|0|abbr=on}} CAT
|7.5 seconds
|{{cvt|230|km/h|0}}
|-
|rowspan="2"|560 SE
|rowspan="2"|W126.038
|09/1988 – 12/1989
|rowspan="14"|([[Mercedes-Benz M117 engine|M 117.968]]) V8
|rowspan="14"|5547 cc
|rowspan="14"|Mechanical continuous multi-point injection<br />with electronic control (Bosch KE-Jetronic)
|{{cvt|220|kW|PS bhp|0}} RÜF
|{{cvt|455|Nm|lbft|0}} RÜF
|rowspan="2"|1800
|6.9 seconds
|{{Convert|250|km/h|0|abbr=on}}
|rowspan="14"|{{convert|13.6|L/100 km|mpgUS|abbr=on}}
|rowspan="2"|1,252 
|-
|09/1988 – 10/1991
|{{cvt|205|kW|PS bhp|0}} CAT
|{{cvt|430|Nm|lbft|0}} CAT 
|7.2 seconds
|{{Convert|242|km/h|0|abbr=on}}
|-
|rowspan="6"|560 SEL
|rowspan="6"|W126.039
|09/1985 – 08/1986
|{{cvt|220|kW|PS bhp|0}} ECE
|{{cvt|455|Nm|lbft|0}} ECE
|rowspan="6"|1830
|6.9 seconds
|{{Convert|250|km/h|0|abbr=on}}
|rowspan="6"|75,071 
|-
|09/1985 – 08/1987
|{{cvt|200|kW|PS bhp|0}} RÜF
|{{cvt|430|Nm|lbft|0}} RÜF 
|7.3 seconds
|{{Convert|235|km/h|0|abbr=on}}
|-
|06/1987 – 12/1989
|{{cvt|220|kW|PS bhp|0}} RÜF
|{{cvt|455|Nm|lbft|0}} RÜF
|6.9 seconds
|{{Convert|250|km/h|0|abbr=on}}
|-
|09/1985 – 08/1987
|{{cvt|178|kW|PS bhp|0}} CAT
|{{cvt|390|Nm|lbft|0}} CAT
|7.6 seconds
|{{Convert|228|km/h|0|abbr=on}}
|-
|09/1987 – 10/1991
|{{cvt|205|kW|PS bhp|0}} CAT
|{{cvt|430|Nm|lbft|0}} CAT
|7.2 seconds
|{{Convert|242|km/h|0|abbr=on}}
|-
|09/1985 – 10/1991
|{{cvt|177.5|kW|PS bhp|0}} US CAT
|{{cvt|389|Nm|lbft|0}} US CAT 
|7.0 seconds (0-60 mph)
|{{Convert|242|km/h|0|abbr=on}}
|-
|rowspan="6"|560 SEC
|rowspan="6"|W126.045
|09/1985 – 10/1991
|{{cvt|220|kW|PS bhp|0}} ECE
|{{cvt|455|Nm|lbft|0}} ECE
|rowspan="6"|1820
|6.9 seconds
|{{Convert|250|km/h|0|abbr=on}}
|rowspan="6"|28,929 
|-
|09/1985 – 08/1987
|{{cvt|200|kW|PS bhp|0}} RÜF
|{{cvt|430|Nm|lbft|0}} RÜF 
|7.3 seconds
|{{Convert|238|km/h|0|abbr=on}}
|-
|06/1987 – 12/1989
|{{cvt|220|kW|PS bhp|0}} RÜF
|{{cvt|455|Nm|lbft|0}} RÜF
|6.9 seconds
|{{Convert|250|km/h|0|abbr=on}}
|-
|09/1985 – 08/1987
|{{cvt|178|kW|PS bhp|0}} CAT
|{{cvt|390|Nm|lbft|0}} CAT
|7.6 seconds
|{{Convert|228|km/h|0|abbr=on}}
|-
|09/1987 – 10/1991
|{{cvt|205|kW|PS bhp|0}} CAT
|{{cvt|430|Nm|lbft|0}} CAT
|7.0 seconds (0-60 mph)
|{{Convert|242|km/h|0|abbr=on}}
|-
|09/1985 – 10/1991
|{{cvt|177.5|kW|PS bhp|0}} US CAT
|{{cvt|389|Nm|lbft|0}} US CAT 
|7.0 seconds (0-60 mph)
|{{Convert|242|km/h|0|abbr=on}}
|-
! colspan="13" style="background:#E8E8E8"| ''Diesel Engines (US and Canada Only)''
|-
|300 SDL
|W126.125
|02/1985 – 09/1987
|([[Mercedes-Benz OM603 engine|OM 603.961]]) Inline 6
|2996 cc
|Precombustion chamber injection<br />(Bosch six-piston inline injection pump)
|{{cvt|143|hp|kW PS bhp|0|order=out}}
|{{cvt|273|Nm|lbft|0}}
|1750
|12.5 seconds
|{{Convert|175|km/h|0|abbr=on}}
|{{convert|12.4|L/100 km|mpgUS|abbr=on}}
|13,830
|-
|350 SD
|W126.134
|rowspan="2"|06/1990 – 08/1991
|rowspan="2"|([[Mercedes-Benz OM603 engine|OM 603.97x]]) Inline 6
|rowspan="2"|3449 cc
|rowspan="2"|Precombustion chamber injection<br />(Bosch six-piston inline injection pump)
|rowspan="2"|{{cvt|100|kW|PS bhp|0}}
|rowspan="2"|{{cvt|310|Nm|lbft|0}}
|1770
|rowspan="2"|13.0 seconds
|rowspan="2"|{{Convert|175|km/h|0|abbr=on}}
|rowspan="2"|{{convert|12.4|L/100 km|mpgUS|abbr=on}}
|2,066
|-
|350 SDL
|W126.135
|1790
|2,925
|-
|}

=== Dimensions and weight ===
{|class=wikitable
|-
!Body style
!Wheelbase
!Length
!Width
!Height
!Curb weight
|-
|Sedan (short-wheelbase)||{{convert|2935|mm|in|1|abbr=on}}||{{convert|4995|-|5020|mm|in|1|abbr=on}}||{{convert|1820|mm|in|1|abbr=on}}||{{convert|1430|-|1437|mm|in|1|abbr=on}}||{{convert|1600|kg|lb|0|abbr=on}}
|-
|Sedan (long-wheelbase)||{{convert|3075|mm|in|1|abbr=on}}||{{convert|5135|-|5160|mm|in|1|abbr=on}}||{{convert|1820|mm|in|1|abbr=on}}||{{convert|1441|mm|in|1|abbr=on}}||{{convert|1600|kg|lb|0|abbr=on}}
|-
|Coupe||{{convert|2850|mm|in|1|abbr=on}}||{{convert|4910|-|4935|mm|in|1|abbr=on}}||{{convert|1828|mm|in|1|abbr=on}}||{{convert|1406|mm|in|1|abbr=on}}||{{convert|1610|kg|lb|0|abbr=on}}
|}

=== Timeline ===
{{Mercedes-Benz W126 timeline}}
{{clear}}

== References ==

=== Notes ===
{{reflist|2}}

=== Bibliography ===
<!-- last updated October 2021 -->

==== General ====
{{refbegin}}
* {{cite book |last=Alder |first=Trevor |title=Mercedes-Benz S-Class Saloons, 1972–91: Road Tests & Articles |year=1996 |publisher=Transport Source Books |asin=B005U5LANQ }}
* {{Barrett-IBG-MB-2}}
* {{Brooklands-MBRT80}}
* {{cite book |editor-last=Clarke |editor-first=R.M. |title=Mercedes S-Class Limited Edition Extra 1980–91 |series=Road Test Series |year=2001 |publisher=Brooklands Books |location=Cobham, Surrey, UK |isbn=1855205815 |editor-mask=6}}
* {{Brooklands-AMG1GP|editor-mask=6}}
* {{MBPersonenwagen-3}}
* {{cite book |last1=Greene |first1=Nik |title=Mercedes-Benz W126 S-Class 1979-1991 |date=2019 |publisher=The Crowood Press |location=Ramsbury, Marlborough, UK |isbn=9781785005411}}
* {{Häußermann-MBS-1952}}
* {{Häußermann-MBLC-1951}}
* {{Hofner-SKMB}}
* {{Hofner-Schrader-MBA-2 |author-mask1=7}}
* {{cite book |last1=Hofner |first1=Heribert |last2=Lange |first2=Hans-Peter |last3=Commertz |first3=Stefan |title=Mercedes-Benz W 126: Die S-Klasse - das beste Auto der Welt |trans-title=Mercedes-Benz W 126: The S-Class - the best car in the world |date=2018 |publisher=Heel Verlag |location=Königswinter, Germany |isbn=9783958435575 |language=de |author-mask1=7}}
* {{cite book |last=Howard |first=Geoffrey |title=Mercedes Benz S-Class and the 190 16E |series=High Performance Series |year=1984 |publisher=Cadogan Publications |location=London |isbn=0947754083 }}
* {{Typenkompass MB-2}}
* {{cite book |last=Lange |first=Matthias |title=Die 126er Codes – jetzt entschlüsselt: Die S-Klasse von 1979 bis 1991 |trans-title=The 126er Codes – now uncrypted: The S-Class from 1979 to 1991 |year=2012 |publisher=Mercedes-Benz Interessengemeinschaft |location=Bonn |isbn=9783981509007 |language=de}}
* {{Larimer-MBBG}}
* {{Meredith-MBS}}
* {{Niemann-PvMB}}
* {{Deutsche Autos-4}}
* {{MBPersonenwagen-2 |author-mask=7}}
* {{cite book |editor-last=Pitt |editor-first=Colin |title=Mercedes-Benz W126 W140 W220 |year=2002 |publisher=Unique Motor Books |location=Hockley, Essex, UK |isbn=1841555150 }}
* {{Röcke-GMSK}}
* {{Röcke-NGMSK}}
* {{Schlegelmilch-M-2013}}
* {{Staud-Lewandowski-MBGCC}}
* {{cite book |last=Storz |first=Alexander Franc |title=Mercedes-Benz S-Klasse: Baureihe W 126 1979–1991 |series=Schrader-Typen-Chronik series |year=2013 |publisher=Motorbuch Verlag |location=Stuttgart |isbn=9783613035812 |language=de}}
* {{Taylor-MB since 1945-4|pages=8–40, 109, 112 }}
* {{Taylor-MB 1990s|pages=9–16, 32–35 }}
* {{Taylor-MB S-Class}}
* {{Vieweg-AMBS}}
* {{cite book |last1=Zoporowski |first1=Tobias |last2=Parish |first2=Julian |title=Mercedes-Benz S-Class: W126-series 1979 to 1991 |series=Essential Buyer's Guide Veloce series |year=2019 |publisher=Veloce Publishing |location=Dorchester, Dorset, UK |isbn=9781787114029}}
{{refend}}

==== Workshop manuals ====
{{refbegin}}
* {{cite book |last1=Greene |first1=Nik |title=Buying and Maintaining a 126 S-Class Mercedes |date=2018 |publisher=The Crowood Press |location=Ramsbury, Marlborough, UK |isbn=9781785002441}}
* {{Chilton-MCSW 1974-84}}
* {{cite book |title=Mercedes S-Klasse 280 S / 280 SE / 380 S / 500 SE |series=Reparaturanleitung series, Band 662. |year=2002 |publisher=Verlag Bucheli |location=Zug, Switzerland |isbn=9783716815854 |language=de}}
* {{cite book |title=Mercedes S-Klasse Serie W126 ab September 79 |series=Reparaturanleitung series, Band 929/930. |year=2012 |publisher=Verlag Bucheli |location=Zug, Switzerland |isbn=9783716817582 |language=de}}
* {{Bentley-MB Technical}}
{{refend}}

== External links ==
{{commons category|Mercedes-Benz W126}}
{{commons category|Mercedes-Benz C126}}
* [https://web.archive.org/web/19990302052806/http://home.concepts.nl/%7Evlimmere/index2.HTM The unofficial W126 page] – history and details of the W126
* [http://www.fuenfkommasechs.de Fuenfkommasechs.de] – German website with vast information on development, model history, engines and innovations
* [https://mercedes-benz-publicarchive.com/marsClassic/en/instance/ko/126-series-S-Class-Saloons-1985---1992.xhtml?oid=4979&relId=1001 Production information, technical data, and media of the Mercedes-Benz Classic Digital Archive]

{{Mercedes-Benz vehicles}}
{{Mercedes-Benz CL-class lineage}}
{{Mercedes-Benz S-Class lineage}}

[[Category:Mercedes-Benz model codes|W126]]
[[Category:Cars introduced in 1979]]
[[Category:1980s cars]]
[[Category:1990s cars]]
[[Category:Full-size vehicles]]
[[Category:Grand tourers]]
[[Category:Rear-wheel-drive vehicles]]
[[Category:Sedans]]
[[Category:Limousines]]
[[Category:Mercedes-Benz vehicles|W126]]
[[Category:Cars discontinued in 1991]]