Mercedes-Benz engine codes start with M for petrol engines and OM for diesels, followed by a three-digit family number: the M272 and M276 are V6s, the M274 and M264 four-cylinders, the M256 an inline-six and the M177 and M178 AMG's 4.0-litre twin-turbo V8s. 24 codes are decoded below with US years, output, models and weak points.
Mercedes-Benz petrol inline-4 engine codes
M274 — 2.0 L turbo inline-4 (2015–2019)
The longitudinal, rear-drive version of the turbocharged, direct-injected four-cylinder family it shares with the transverse M270. It uses a single turbocharger and direct petrol injection. US cars used the 2.0 litre version rated at 241 hp. A 1.6 litre version and lower-output 2.0 litre tunes were sold in other markets. It was succeeded by the M264 around 2018–2019.
- US output:
- 241 hp
- Displacement:
- 1,991 cc
US models: W205 C 300, X253 GLC 300, W213 E 300, R172 SLC 300
Details and pre-purchase checks: M274 camshaft adjuster wear and oil reaching the engine wiring
Spec tables: W205 C-Class specs · W213 E-Class specs · X253 GLC specs
Sources: Mercedes-Benz M274 engine – Wikipedia
M270 — 2.0 L turbo inline-4 (2014–2020)
The transverse version of the turbocharged four-cylinder family, built for front-drive and 4MATIC compact models. US buyers got the 2.0 litre version rated at 208 hp in the first-generation CLA 250 and GLA 250. Markets outside the US also had 1.6 litre versions in A-Class and B-Class models. The AMG 45 models of the same era used the separate M133 engine, and the M260 replaced the M270.
- US output:
- 208 hp
- Displacement:
- 1,991 cc
US models: C117 CLA 250, X156 GLA 250
Details and pre-purchase checks: 7G-DCT dual-clutch shudder and jerky low-speed engagement · 7G-DCT dual-clutch low-speed shudder
Spec tables: C117 CLA-Class specs · X156 GLA-Class specs
Sources: Mercedes-Benz M270 engine – Wikipedia
M260 — 2.0 L turbo inline-4 (2019–present)
The transverse 2.0 litre turbo four used in the second-generation compact cars, succeeding the M270. It has a twin-scroll turbocharger and direct injection. US output ranges from about 188 hp in the A 220 to about 221 hp in 250 models; AMG 35 models use a 302 hp version. Its longitudinal twin is the M264, and the AMG 45 models use the separate M139.
- US output:
- 221–302 hp
- Displacement:
- 1,991 cc
US models: W177 A 220, W177 AMG A 35, C118 CLA 250, C118 AMG CLA 35, H247 GLA 250, H247 AMG GLA 35, X247 GLB 250, X247 AMG GLB 35
Spec tables: C118 CLA-Class specs · H247 GLA-Class specs · X247 GLB-Class specs
Sources: Mercedes-Benz M260/M264 engine – Wikipedia
M264 — 2.0 L turbo (48v belt starter-generator on some versions) inline-4 (2019–2023)
The longitudinal, rear-drive version of the M260 design, replacing the M274. US models used a 2.0 litre version rated at about 255 hp. It has a twin-scroll turbo and intake camshaft adjustment, and some versions add a 48-volt belt-driven starter-generator that Mercedes markets as EQ Boost. A 1.5 litre variant was sold outside the US. The M254 has since replaced it in most models.
- US output:
- 255 hp
- Displacement:
- 1,991 cc
US models: W205 C 300, W213 E 350, X253 GLC 300, V167 GLE 350
Spec tables: W205 C-Class specs · W213 E-Class specs · X253 GLC specs · V167 GLE specs
Sources: Mercedes-Benz M260/M264 engine – Wikipedia
M254 — 2.0 L turbo + 48v integrated starter-generator inline-4 (2022–present)
A 2.0 litre turbo four that belongs to the same modular family as the M256 inline-six and succeeds the M274/M264. Non-plug-in versions pair it with a 48-volt integrated starter-generator, a small electric motor between engine and transmission that adds roughly 20 hp for short bursts and handles engine restarts. Plug-in hybrid C-, E- and GLC-Class models use other tunes, and a Euro 7 update arrives in later models.
- US output:
- 255 hp
- Displacement:
- 1,999 cc
US models: W206 C 300, X254 GLC 300, W214 E 350, C236 CLE 300
Spec tables: W206 C-Class specs · W214 E-Class specs · X254 GLC specs · V167 GLE specs
Sources: Mercedes-Benz C-Class (W206) – Wikipedia · Mercedes-Benz E-Class (W214) – Wikipedia · New Mercedes four-cylinder engine M254 with ISG and 48V system – Mercedesblog
M139 — 2.0 L turbo (electric exhaust-gas turbocharger on m139l versions) inline-4 (2021–present)
AMG's hand-built 2.0 litre turbo four, mounted with the turbo and exhaust at the rear of the engine. It combines direct and port injection and uses a twin-scroll turbo. Later longitudinal versions (M139l) add an electrically assisted turbocharger derived from Formula 1 technology. In the C 63 S and GLC 63 S E Performance plug-in hybrids the engine alone makes about 469 hp, with far more combined system output.
- US output:
- 375–416 hp
- Displacement:
- 1,991 cc
US models: C118 AMG CLA 45, H247 AMG GLA 45, W206 AMG C 43, X254 AMG GLC 43, R232 AMG SL 43, C192 AMG GT 43 Coupe, W206 AMG C 63 S E Performance, X254 AMG GLC 63 S E Performance
Spec tables: W206 C-Class specs · C118 CLA-Class specs · H247 GLA-Class specs · X254 GLC specs · C192 GT specs · R232 SL specs
Sources: Mercedes-AMG M139 engine – Wikipedia · Mercedes-Benz C-Class (W206) – Wikipedia · 2023 Mercedes-AMG SL43 US pricing – Motor1
Mercedes-Benz petrol v6 engine codes
M112 — 3.2 L naturally aspirated V6 (1998–2005)
A 90-degree V6 with a single overhead camshaft per bank, three valves per cylinder and twin-spark ignition. US cars used 2.6, 2.8, 3.2 and 3.7 litre versions; the 3.2 litre was the most common. AMG added an IHI twin-screw supercharger to the 3.2 litre for the C 32 and SLK 32, assembled in Affalterbach. The family was phased out in favour of the M272 from the 2006 model year.
- US output:
- 168–349 hp
- Displacement:
- 3,199 cc
US models: W202 C 280, W203 C 240 / C 320, W203 C 32 AMG, W210 E 320, W211 E 320, W163 ML 320 / ML 350, C208 CLK 320, C209 CLK 320, R170 SLK 320, R170 SLK 32 AMG
Spec tables: W203 C-Class specs · W211 E-Class specs
Sources: Mercedes-Benz M112 engine – Wikipedia
M272 — 3.5 L naturally aspirated V6 (2006–2013)
A 90-degree, four-valve DOHC V6 with a balance shaft and variable valve timing on both camshafts, replacing the M112. US cars used 2.5, 3.0 and 3.5 litre versions; the 3.5 litre was by far the most common. Some later 3.5 litre versions had a higher output, and a direct-injected CGI variant existed for other markets. The M276 replaced it from 2011–2012.
- US output:
- 201–268 hp
- Displacement:
- 3,498 cc
US models: W203 C 230 / C 280 / C 350, W204 C 300 / C 350, W211 E 350, W212 E 350, C209 CLK 350, R171 SLK 280 / SLK 300 / SLK 350, W164 ML 350, W251 R 350, X204 GLK 350, W221 S 400 Hybrid
Documented weak points
- Early engines (2005–2007 models, serial numbers up to 2729..30 468993) are known for premature balance shaft sprocket wear; the Seifi v. Mercedes-Benz USA class settlement (N.D. Cal., 2015) extended coverage to 10 years / 125,000 miles.
- The plastic lever that operates the variable-length intake manifold runners can break; the factory part is sold only as a complete manifold.
Details and pre-purchase checks: M272 V6 balance shaft sprocket wear · M272 balance shaft / M273 idler gear sprocket wear
Spec tables: W203 C-Class specs · W204 C-Class specs · W211 E-Class specs · W212 E-Class specs · W221 S-Class specs · W164 GLE specs
Sources: Mercedes-Benz M272 engine – Wikipedia · Mercedes-Benz M272 and M273 engine lawsuit – CarComplaints.com
M276 — 3.0 L naturally aspirated (3.5 l) or twin-turbo (3.0 l and 3.5 l) V6 (2012–2021)
A 60-degree, direct-injected V6 that replaced the M272. The naturally aspirated 3.5 litre version (about 302 hp in most US cars) ran from 2012 to roughly 2018, with a detuned version in the W204 C 300 4MATIC. A twin-turbo 3.0 litre followed in 400, 450 and AMG 43 models at about 329 to 396 hp, and a twin-turbo 3.5 litre appeared in some 400 models. The M256 inline-six replaced it.
- US output:
- 302–396 hp
- Displacement:
- 2,996 cc
US models: W204 C 300 4MATIC / C 350, W212 E 350 / E 400, C207 E 400 Coupe, W166 ML 350 / GLE 350 / GLE 400, X204 GLK 350, W251 R 350, R172 SLK 350, W205 C 400 / C 450 AMG / AMG C 43, X253 AMG GLC 43, R172 AMG SLC 43, R231 SL 400 / SL 450, X166 GL 450 / GLS 450, W213 E 400 / AMG E 43, C218 CLS 400
Documented weak points
- Owners of early engines (roughly 2012–2014) report a brief rattle on cold start, commonly attributed to camshaft adjusters or chain tensioners; this is documented in owner forums rather than in a factory recall.
Details and pre-purchase checks: M276 V6 cold-start rattle (camshaft adjusters / chain tensioners)
Spec tables: W204 C-Class specs · W205 C-Class specs · W212 E-Class specs · W213 E-Class specs · W222 S-Class specs · X253 GLC specs · W166 GLE specs · X166 GLS specs
Sources: Mercedes-Benz M276 engine – Wikipedia · M276 2012 E350 coupe startup rattle – MBWorld forum
Mercedes-Benz petrol v8 engine codes
M113 — 5.0 L naturally aspirated (supercharged m113k in amg 55 models) V8 (1998–2011)
The V8 sibling of the M112, sharing its three-valve, twin-spark layout. US versions came in 4.3, 5.0 and 5.4 litres, with the 5.0 litre in most 430/500 models. AMG's 5.4 litre ran naturally aspirated in early 55 models and with a twin-screw supercharger (M113K) from about 2002 in cars such as the E 55, S 55, SL 55 and G 55. The supercharged M155 in the SLR McLaren is a separate derivative.
- US output:
- 302–510 hp
- Displacement:
- 4,966 cc
US models: W210 E 430, W220 S 430 / S 500, W163 ML 430 / ML 500, C215 CL 500, R230 SL 500, W211 E 500, C209 CLK 500, W463 G 500, W164 ML 500, W251 R 500, W203 C 55 AMG, R171 SLK 55 AMG, W211 E 55 AMG, C219 CLS 55 AMG, R230 SL 55 AMG, W463 G 55 AMG
Spec tables: W203 C-Class specs · W211 E-Class specs · W164 GLE specs · W463 G-Class specs · R230 SL specs
Sources: Mercedes-Benz M113 engine – Wikipedia
M273 — 5.5 L naturally aspirated V8 (2007–2015)
The V8 counterpart of the M272, sharing its four-valve DOHC design and much of its architecture. Most US cars used the 5.5 litre version rated at 382 hp, which brought the 550 badge to the US lineup; the GL 450 used a 4.7 litre version rated at 335 hp. The twin-turbo M278 replaced it in most models from 2011, though the G 550 kept it through 2015.
- US output:
- 335–382 hp
- Displacement:
- 5,461 cc
US models: W211 E 550, W212 E 550, W221 S 550, C216 CL 550, C219 CLS 550, C209 CLK 550, R230 SL 550, W164 ML 550, X164 GL 450 / GL 550, W463 G 550
Documented weak points
- Early engines (2006–2007 models, serial numbers up to 2739..30 088611) can suffer premature idler gear wear in the timing drive; the same 2015 class settlement as the M272 extended coverage to 10 years / 125,000 miles.
- Wikipedia notes the intake manifold lever issue seen on the M272 also affects the M273, though to a lesser extent.
Details and pre-purchase checks: M273 V8 idler gear sprocket wear
Spec tables: W211 E-Class specs · W212 E-Class specs · W221 S-Class specs · W164 GLE specs · X164 GLS specs · W463 G-Class specs · R230 SL specs
Sources: Mercedes-Benz M273 engine – Wikipedia · Mercedes-Benz M272 engine – Wikipedia (M273 manifold note) · Mercedes-Benz M272 and M273 engine lawsuit – CarComplaints.com
M278 — 4.7 L twin-turbo V8 (2011–2020)
A 4.7 litre, direct-injected, twin-turbocharged V8 that replaced the naturally aspirated M273 in most 550 models while using less fuel. Output varied by model: about 402 hp in the E, CLS and M-Class, about 429 hp in the earlier S, CL, SL and GL, about 449 hp in the W222 S-Class, and about 362 hp in the GL 450. The AMG M157 is its 5.5 litre derivative.
- US output:
- 362–449 hp
- Displacement:
- 4,663 cc
US models: W221 S 550, W222 S 550, C217 S 550 Coupe, C216 CL 550, C218 CLS 550, W212 E 550, W166 ML 550, X166 GL 450 / GL 550 / GLS 550, R231 SL 550
Spec tables: W212 E-Class specs · W221 S-Class specs · W222 S-Class specs · W166 GLE specs · X166 GLS specs · R231 SL specs
Sources: Mercedes-Benz M278 engine – Wikipedia
M176 — 4.0 L twin-turbo (hot-v); 48v eq boost on later versions V8 (2016–present)
The wet-sump, non-AMG-badged member of the 4.0 litre hot-V V8 family that also includes the AMG M177 and M178. Both turbochargers sit inside the cylinder vee for short exhaust paths. It replaced the M278 in 550/560 models and later gained a 48-volt EQ Boost starter-generator in 580 models. US output ranges from about 416 hp in the G 550 to about 550 hp in the Maybach GLS 600.
- US output:
- 416–530 hp
- Displacement:
- 3,982 cc
US models: W463 G 550, W222 S 560, C217 S 560 Coupe / Cabriolet, X222 Maybach S 560, V167 GLE 580, X167 GLS 580 / Maybach GLS 600, W223 S 580
Documented weak points
- NHTSA recall 20V-173 covered 9,791 2018–2019 S 560 and Maybach S 560 vehicles because two engine oil plugs could fail under high load and leak oil; dealers added a retaining plate free of charge.
Spec tables: W222 S-Class specs · W223 S-Class specs · V167 GLE specs · X167 GLS specs · W463 G-Class specs · W463A G-Class specs
Sources: Mercedes-AMG M177/M178 (incl. M176) engine – Wikipedia · NHTSA recall 20V-173
M177 — 4.0 L twin-turbo (hot-v) V8 (2015–present)
AMG's wet-sump 4.0 litre twin-turbo V8, hand-assembled in Affalterbach and built for its sedans, SUVs and four-door GT. C 63 and GLC 63 versions use single-scroll turbos, while E 63 and S 63 versions add twin-scroll turbos and cylinder deactivation. Later SUV versions gained a 48-volt starter-generator. Aston Martin also uses the engine. US output ranges from about 469 hp to about 630 hp.
- US output:
- 469–630 hp
- Displacement:
- 3,982 cc
US models: W205 AMG C 63 / C 63 S, X253 AMG GLC 63 / GLC 63 S, W213 AMG E 63 / E 63 S, W222 AMG S 63, C217 AMG S 63 Coupe, X290 AMG GT 63 / GT 63 S 4-Door, W463 AMG G 63, V167 AMG GLE 63 S, X167 AMG GLS 63, R232 AMG SL 63
Spec tables: W205 C-Class specs · W213 E-Class specs · W222 S-Class specs · W223 S-Class specs · X253 GLC specs · V167 GLE specs · X167 GLS specs · W463A G-Class specs
Sources: Mercedes-AMG M177/M178 engine – Wikipedia
M178 — 4.0 L twin-turbo (hot-v) V8 (2016–2022)
The dry-sump version of AMG's 4.0 litre hot-V twin-turbo V8, created for the two-door AMG GT sports car. Dry-sump lubrication lets the engine sit lower in the chassis and keeps oil supply steady under hard cornering. US output started at about 456 hp in the original GT and rose through the GT S, GT C and GT R, peaking at about 720 hp in the flat-plane-crank GT Black Series.
- US output:
- 456–720 hp
- Displacement:
- 3,982 cc
US models: C190 AMG GT / GT S / GT C, C190 AMG GT R / GT R Pro, C190 AMG GT Black Series, R190 AMG GT Roadster / GT C Roadster
Spec tables: C190 GT specs
Sources: Mercedes-AMG M177/M178 engine – Wikipedia
M155 — 5.4 L supercharged V8 (2005–2009)
A hand-built, supercharged 5.4 litre V8 developed by AMG for the Mercedes-Benz SLR McLaren, which was built by McLaren in Woking. It is related to the M113K but uses dry-sump lubrication so it could sit low and far back in the front-mid-engine layout. Standard cars made about 617 hp, and the 722 Edition raised that to about 641 hp.
- US output:
- 617–641 hp
- Displacement:
- 5,439 cc
US models: C199 SLR McLaren, C199 SLR McLaren 722 Edition, R199 SLR McLaren Roadster
Sources: Mercedes-Benz M113 engine (M155 section) – Wikipedia
M156 — 6.2 L naturally aspirated V8 (2007–2015)
The first V8 designed entirely by AMG, a naturally aspirated 6.2 litre engine marketed as the "6.3". It has four valves per cylinder and revs past 7,000 rpm. Output varied by model, from about 451 hp in the C 63 to about 518 hp in the later S, E, SL and CL 63. The twin-turbo M157 replaced it in most models from 2011, but the C 63 kept it through 2015.
- US output:
- 451–518 hp
- Displacement:
- 6,208 cc
US models: W204 C 63 AMG, W211 E 63 AMG, W212 E 63 AMG, C209 CLK 63 AMG, C219 CLS 63 AMG, W221 S 63 AMG, C216 CL 63 AMG, R230 SL 63 AMG, W164 ML 63 AMG, W251 R 63 AMG
Documented weak points
- Wikipedia lists crankcase breather diaphragm and hose failures, which can cause oil consumption and misfires (the section is marked as unsourced).
- Wikipedia also lists wear of lifters, camshafts and cam adjusters, usually noticed as a ticking sound at cold start (unsourced section).
- Head bolt problems on 2007–2011 engines are mentioned in the same unsourced Wikipedia section.
Spec tables: W204 C-Class specs · W211 E-Class specs · W212 E-Class specs · W221 S-Class specs · W164 GLE specs · R230 SL specs
Sources: Mercedes-AMG M156/M159 engine – Wikipedia
M157 — 5.5 L twin-turbo V8 (2011–2019)
AMG's 5.5 litre twin-turbo V8, derived from the M278 and introduced to replace the larger naturally aspirated M156 with better fuel economy and much more torque. Output depended on the model and whether the AMG Performance Package or an S-Model was chosen, ranging from about 518 hp to about 577 hp in the US. A naturally aspirated relative, the M152, powered the R172 SLK 55 AMG.
- US output:
- 518–577 hp
- Displacement:
- 5,461 cc
US models: W221 S 63 AMG, W222 S 63 AMG, C217 S 63 AMG Coupe, C216 CL 63 AMG, W212 E 63 AMG, C218 CLS 63 AMG, W166 ML 63 AMG / AMG GLE 63, X166 GL 63 AMG / AMG GLS 63, W463 G 63 AMG, R231 SL 63 AMG
Details and pre-purchase checks: M278 / M157 twin-turbo V8 timing chain stretch
Spec tables: W212 E-Class specs · W221 S-Class specs · W222 S-Class specs · W166 GLE specs · X166 GLS specs · W463 G-Class specs · R231 SL specs
Sources: Mercedes-AMG M157 engine – Wikipedia · Mercedes-Benz M278 engine – Wikipedia
M159 — 6.2 L naturally aspirated V8 (2011–2015)
A high-output, dry-sump development of the 6.2 litre M156, built for the SLS AMG gullwing coupe and roadster and the first-generation AMG GT3 race car. The dry sump let the engine sit lower in the front-mid-engine chassis. US output started at about 563 hp, rose to about 583 hp in the SLS AMG GT, and peaked at about 622 hp in the Black Series, which revved higher.
- US output:
- 563–622 hp
- Displacement:
- 6,208 cc
US models: C197 SLS AMG Coupe, R197 SLS AMG Roadster, C197 SLS AMG GT, C197 SLS AMG Black Series
Sources: Mercedes-AMG M156/M159 engine – Wikipedia
Mercedes-Benz petrol v12 engine codes
M275 — 5.5 L twin-turbo V12 (2003–2014)
An all-aluminium, 60-degree twin-turbocharged V12 with a single overhead camshaft per bank and three valves per cylinder. The 5.5 litre version powered the 600 models, while AMG built a 6.0 litre version for the 65 models with roughly 1,000 Nm of torque. The SL 65 Black Series used larger turbochargers. The related M285 powered Maybach 57 and 62 models, and the updated M279 succeeded it.
- US output:
- 493–661 hp
- Displacement:
- 5,513 cc
US models: W220 S 600, W221 S 600, C215 CL 600, C216 CL 600, R230 SL 600, W220 S 65 AMG, W221 S 65 AMG, C215 CL 65 AMG, C216 CL 65 AMG, R230 SL 65 AMG, R230 SL 65 AMG Black Series
Spec tables: W221 S-Class specs · R230 SL specs
Sources: Mercedes-Benz M275 engine – Wikipedia
M279 — 6.0 L twin-turbo V12 (2013–present)
An updated 6.0 litre twin-turbo V12 that succeeded the M275 in AMG 65 and Maybach models, keeping the three-valve, single-camshaft-per-bank layout. Most US versions are rated at about 621 hp with roughly 1,000 Nm of torque, with early G 65 models listed lower. A closely related non-AMG version, the M277, powered US S 600 and Maybach S 600 models from 2015. It remains in the current Maybach S 680.
- US output:
- 621 hp
- Displacement:
- 5,980 cc
US models: R231 SL 65 AMG, W222 AMG S 65, C217 AMG S 65 Coupe / Cabriolet, W463 G 65 AMG, X222 Maybach S 650, Z223 Maybach S 680
Spec tables: W222 S-Class specs · W223 S-Class specs · W463 G-Class specs · R231 SL specs
Sources: Mercedes-Benz M279 engine – Wikipedia