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What does the K in the W211 E55's M113K actually mean?
The badge spells it out
Forums and the press call the W211 E55 AMG's engine the M113K. That's an enthusiast shorthand, not what's printed on the car. The car's own badge reads 'V8 Kompressor'.
What you'd notice: The small 'V8 Kompressor' badges on the front wings.
Source: PistonHeads, 2018
The V8 came before the K
M113 is a Mercedes V8 family. The earlier W210 E55 AMG used it without a supercharger: 5.4 liters, 349 hp and 391 lb-ft (US ratings), assembled by AMG at Affalterbach.
Source: Carscoops, Dec 2020; PistonHeads, Jan 2020
K means Kompressor
For the W211 E55, AMG added an IHI screw-type supercharger plus an intercooler. MotorWeek lists 13.1 psi of boost. K is Kompressor, German for supercharger.
Source: MotorWeek, 2004 E55 AMG test; PistonHeads, 2015
The jump from W210 to W211
In US ratings, the W210 E55's 349 hp became 469 hp in the W211, and its 391 lb-ft became 516.
Source: Carscoops; MotorWeek; PistonHeads
A four-door with that torque
MotorWeek timed it at 4.4 seconds to 60 mph; evo quotes 4.7 seconds to 62 mph, with a 155 mph top speed. Opinion: torque from 2,650 rpm helps explain its used-car cult following.
Source: MotorWeek, 2004 test; evo, Dec 2024
Mercedes' K once meant short
On the 1928 SSK, Mercedes says the K means kurz, short: a 2,950 mm wheelbase instead of 3,400. It was supercharged too, but its K didn't say so. The 1934 500 K used K for Kompressor.
Source: Mercedes-Benz Media, 2019; Conceptcarz
Sources and assumptions
- Mercedes-Benz Media: Die Mercedes-Benz Kompressorwagen der S-Reihe (Stuttgart, 5 April 2019): On the SSK the extra K stands for 'Kurz' (short); SSK developed in 1928 for hill climbs, wheelbase 2,950 mm instead of 3,400 mm; the S-series cars were supercharged (Kompressor/mechanischer Lader); S = Sport, SS = Super Sport (checked 2026-10-02)
- Conceptcarz: 1935 Mercedes-Benz 540K: 'K' for Kompressor (supercharger) to distinguish it from the 500 sedan without supercharger; 500K introduced 1934 at the Berlin Motor Show; 5,018 cc; 100 hp without, 160 hp with supercharger; Roots supercharger engaged by pressing the accelerator past a pressure point (checked 2026-10-02)
- MotorWeek road test: 2004 Mercedes-Benz E55 AMG (Program #2247): 5.4-liter Kompressor V8, 469 hp, 516 lb-ft, peak torque from 2,650 rpm, 13.1 psi boost from a screw-type supercharger with intercooler, 0-60 mph in 4.4 s, base price $76,720 (checked 2026-10-02)
- PistonHeads: Mercedes E55 AMG PH Used Buying Guide (Alisdair Suttie, 31 Oct 2018): W211 E55: 5,439cc supercharged V8, 476 PS @ 6,100 rpm, 516 lb-ft @ 2,650-4,500 rpm; subtle 'V8 Kompressor' badges on the front wings (checked 2026-10-02)
- PistonHeads: Mercedes E55 AMG (W211) Market Watch (Guy R Baker, 17 Nov 2015): W211 E55 used an IHI supercharger; the engine is called the 'M113 Kompressor'; 516 lb-ft from 2,650 rpm (checked 2026-10-02)
- evo: Mercedes-Benz E55 AMG (W211, 2003-2006) review, specs and buying guide (Sam Jenkins, 10 Dec 2024): 'the 5.4-litre supercharged M113K V8'; 469 bhp @ 6,100 rpm; 516 lb-ft @ 2,650-4,500 rpm; 0-62 mph 4.7 s; top speed 155 mph; W211 E55 2003-2006 (checked 2026-10-02)
- CarBuzz: This Supercharged Sports Sedan Was An Underrated Luxury Hero (Ryan De Villiers, 7 Apr 2025): W211 E55 AMG produced 2003-2006; M113K V8 with Lysholm supercharger; 5.4L, 469 hp @ 6,100 rpm, 516 lb-ft @ 2,650 rpm; the E63 replaced it with a naturally aspirated 6.2-liter M156 V8 (checked 2026-10-02)
- Carscoops: The Forgotten AMG: Why Mercedes' W210 E55 Is Worth Your Attention (Andrew Gutman, 26 Dec 2020): W210 E55 AMG used a modified naturally aspirated 5.4-liter M113 V8 making 349 hp and 391 lb-ft, hand-built at Affalterbach; 0-60 mph 4.9 s (checked 2026-10-02)
- PistonHeads: Mercedes E55 AMG (W210) Brave Pill (Mike Duff, 4 Jan 2020): W210 E55 engine was Mercedes' triple-valve V8 assembled by AMG in Affalterbach; 'The naturally-aspirated M113 V8'; 391 lb-ft (checked 2026-10-02)
- Auto123: 2004 Mercedes E-Class E55 AMG Sedan technical specs: North American spec sheet lists '5.5L V8 SOHC 24 valves Supercharged', 469 hp @ 6100 rpm, 5-speed Speedshift automatic (shows why 5.5L appears in some listings) (checked 2026-10-02)
Assumptions:
- Horsepower and torque are US ratings (469 hp / 516 lb-ft; W210: 349 hp / 391 lb-ft). The metric rating for the W211 E55 is 476 PS. Don't mix units on one slide.
- 'M113K' is the name used by the press (evo, CarBuzz) and owners. Mercedes badges the car 'V8 Kompressor' and I could not open a Mercedes page that prints 'M113K', so the post must say enthusiasts and the press call it M113K, not that it is the factory code on the car. Mercedes' archive reportedly lists the engine as 'M 113 E 55 ML', but its pages returned 403, so that designation stays out of the post.
- Displacement is 5,439 cc (5.4 L) per PistonHeads. The '55' badge and some US spec sheets (Auto123: 5.5L) round it differently; the post should explain that rather than pick one silently.
- W210 E55 model years were not confirmed in an opened source, so the W210 is named without years. W211 E55 = 2003-2006 per evo and CarBuzz (UK sales from 2002 per PistonHeads).
- 0-60 times differ by tester (MotorWeek 4.4 s to 60 mph; evo 4.7 s to 62 mph). Cite the tester with any time used.
- The 500 K 'K = Kompressor' explanation comes from Conceptcarz (secondary). The Mercedes public archive and Petersen pages blocked fetching (403/429). The SSK 'K = kurz' comes from Mercedes-Benz Media (primary).
- 'Cult used-car bargain' is opinion and must be labeled as such if used.
Photos:
The short version
- M113 is the V8 family.
- K is Kompressor, German for supercharger.
- The W211 E55 made 469 hp (US rating).
- On the 1928 SSK, K meant kurz.
