Mercedes C-Class W206 Engines — The Complete UK Guide
Every engine fitted to the W206 saloon — from the M264 1.5-litre mild-hybrid to the M254 2.0-litre petrols, the OM654 diesels, and the electrified M139l in the AMG C43 and C63. All W206 engines are four-cylinders with 48V mild-hybrid assistance — Mercedes has dropped six-cylinders entirely from this generation. Backed by real UK W206 enquiries in 2025 [MB-VERIFIED].
Explore W206 Engines
Mercedes C-Class W206 Engine Codes — The Complete Database
Every engine fitted to the W206 saloon specifically — all are four-cylinder turbocharged units with 48V mild-hybrid assistance, marking the first time Mercedes has offered the C-Class without six-cylinder options .
Overview
Mercedes C-Class W206 — Overview
The W206 is the fifth-generation C-Class, launched in March 2021 as the successor to the W205 .
It sits on the MRA2 platform with a 100 kg weight reduction and a longer wheelbase . For the first time, every W206 C-Class is equipped with a four-cylinder engine with an integrated starter generator and a 48-volt electrical system — Mercedes has dropped six-cylinder engines entirely from this generation . The engine range spans the M264 1.5-litre petrol, the M254 2.0-litre petrol, the OM654 2.0-litre diesel, and the M139l in AMG models. Plug-in hybrid options (C300e, C350e, C63 S E-Performance) are available with a 25.4 kWh battery.
Key Facts
Platform
Mercedes MRA2
Predecessor
W205
Successor
— (current generation)
Sibling body styles in this generation
S206 Estate, V206 long-wheelbase saloon
Market Intelligence
The W206 C-Class is the current-generation model; enquiry volumes are growing as early cars (2021–2022) exit manufacturer warranty and enter the used market.
Best & Worst Engines
Best Diesel Overall
OM654.820 (C220d/C300d)
“The 2.0-litre OM654 is a proven, robust diesel with a genuine 200,000-mile-plus lifespan. The 48V mild-hybrid system adds refinement, and the C300d's 261bhp makes it genuinely quick. Early OM654 units had some turbocharger issues, but these appear to have been resolved by 2022. It's the W206's most dependable engine.”
Who it's for: buyers who want diesel economy and torque without compromising on refinement.
Best Petrol Overall
M264.915 (C200)
“The 1.5-litre M264 offers 201bhp with 48V mild-hybrid assistance — it's smooth, refined, and more than enough for UK roads. The M264 is a proven engine from the W205 era, carried over with mild-hybrid additions, making it the safer bet compared to the newer M254.”
Who it's for: buyers who want a modern, efficient petrol without the M254's reliability question marks.
Highest Risk
M254.920 (C300/C300e/C350e)
“The M254 is the newest engine in the W206 lineup, replacing the M264. But it comes with reported issues: excessive oil consumption, camshaft adjuster failure (confirmed by Mercedes internal bulletin LI05.20-P-080257), and variator problems at relatively low mileage . These are still being understood, and long-term reliability is unproven.”
Who it's for: buyers willing to accept teething issues for the latest technology.
Most Expensive Failure
M139l (AMG C63 S E-Performance)
“The M139l in the C63 is the most complex engine ever fitted to a C-Class — 2.0 litres, 476bhp from the engine alone, plus a rear-axle electric motor for 680bhp combined. When something goes wrong, it goes wrong expensively. The electric turbocharger, the hybrid system, and the sheer labour intensity of working on this engine mean replacement costs will be eye-watering.”
Who it's for: buyers with deep pockets who want the most powerful four-cylinder production car ever.
Best Value
OM654.820 (C220d)
“The C220d is the volume diesel for good reason — 197bhp, genuine 50+ mpg, and the same robust OM654 as the more powerful C300d. It's cheaper to buy, cheaper to run, and cheaper to replace than the petrol alternatives. The sweet spot in the W206 range.”
Who it's for: buyers who want the best combination of economy, performance, and reliability.
Most Overlooked
M264.915 (C180)
“The C180 is often overlooked in favour of the C200, but it's the same 1.5-litre M264 engine with 168bhp instead of 201bhp. It's cheaper to buy, cheaper to insure, and fundamentally the same reliable engine. For most UK buyers, 168bhp is more than enough.”
Who it's for: budget-conscious buyers who want a premium badge without the premium running costs.
Mercedes C-Class W206 — Ownership Economics
The W206 rule
A £3,000–£5,000 OM654 recon against a £25,000 W206 sits at 12–20% of the car's value — comfortably safe. Even the M254 at £3,500–£6,000 against a £22,000 C300 is 16–27% — well within our 70% Mercedes threshold. The W206 is a new-generation car with strong retained values; engine replacement is financially viable across the range. The only exception is the AMG C63 — but if you can afford a £70,000+ car, you can afford the maintenance.
Common Problems
W206 Engine Replacement Costs — By Engine and Condition
No Generation variance from the Model Page's baseline figures — W206 saloon shares identical engine-bay access with its S206 estate sibling, so costs are inherited directly per the Authority Model, with no divergence note required. M139l costs reflect AMG-specific parts, the electric turbocharger, and specialist labour requirements.
Core Variants
Core Variants
Market Intelligence
Most Requested E90 Engines (2025)
- 1.1. OM654.820 (C220d) — volume diesel [PATTERN DATA]
- 2.2. M264.915 (C200) — volume petrol [PATTERN DATA]
- 3.3. M139l (AMG C43/C63) — performance niche [PATTERN DATA]
Most Requested E90 Variants
- 1.1. C220d
- 2.2. C200
- 3.3. AMG C43 [PATTERN DATA]
Average E90 Replacement Cost
£2,500–£6,000 reconditioned, supply only [MB-QUOTE]
Most Common E90 Failures
- 1.1. M254 oil consumption/camshaft adjusters
- 2.2. 48V mild-hybrid system issues
- 3.3. OM654 turbocharger (early units) [PATTERN DATA]
Mercedes C220d W206 (OM654)
4
enquiries
Mercedes C300 W206 (M254)
3
enquiries
Mercedes AMG C43 W206 (M139l)
2
enquiries
FAQ
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