Mercedes S-Class W220 Engines — The Complete UK Guide
Every engine fitted to the fourth-generation S-Class flagship — from the V6 M112 and V8 M113 to the V12 M137 and the OM648 straight-six diesel. Real UK costs, honest reliability data, and the engine range that defined Mercedes' luxury saloon at the turn of the millennium. Backed by 880+ real UK enquiries in 2025 [MB‑VERIFIED].
Explore W220 Engines
Mercedes S-Class W220 Engine Codes — The Complete Database
Every engine fitted to the W220 specifically — including the pre- and post-facelift changes, AMG variants, and the short-lived M137 V12.
Overview
Mercedes S-Class W220 — Overview
The W220 is the fourth generation of the Mercedes‑Benz S‑Class, launched in 1998 as the successor to the W140.
Built on a new platform that was slightly smaller externally than its predecessor but offered greater interior volume, it introduced a range of advanced technologies including the COMAND infotainment system and Keyless-Go. The engine range spanned from the 2.8‑litre M112 V6 to the 6.3‑litre M137 V12, with AMG variants delivering up to 444 bhp. A significant facelift arrived in 2002, bringing new engines including the M275 biturbo V12 and the improved OM648 straight-six diesel. Production ended in July 2005, succeeded by the W221.
Key Facts
Platform
Mercedes W220 (shared with C215 CL-Class)
Predecessor
W140 (1991–1998)
Successor
W221 (2005–2013)
Sibling body styles in this generation
C215 (CL-Class coupé)
Market Intelligence
The W220 S‑Class generated 880+ real UK engine enquiries in 2025 [MB‑VERIFIED], concentrated on the OM648 diesel and M113 V8 as the most‑requested powertrains.
Best & Worst Engines
Best Diesel Overall
OM648.960 (S 320 CDI, facelift)
“Mercedes' improved 3.2‑litre straight‑six diesel, introduced with the 2002 facelift, replaced the problematic OM613 with a more refined and reliable unit. It delivers 204 bhp with strong low‑end torque and better fuel economy than its predecessor.”
Who it's for: buyers who want a modern, efficient diesel for high‑mileage luxury motoring.
Best Petrol Overall
M113.966 (S 500 4MATIC)
“Mercedes' 5.0‑litre V8, mated to the 4MATIC all‑wheel drive system, delivers 306 bhp with a silky, effortless character. The M113 is one of Mercedes' most robust V8 engines, with fewer of the issues that plague the M137 V12.”
Who it's for: buyers who want V8 power and all‑weather capability.
Highest Risk
M137.970/980 (S 600 / S 63 AMG)
“The M137 V12 has gone on to be regarded as one of Mercedes‑Benz's least reliable engines ever made. Along with a host of other issues, one of the main concerns is cylinder wall deformation, allowing oil to pass into the combustion chamber. The 6.3‑litre S 63 AMG variant is even more problematic.”
Who it's for: collectors with deep pockets and a specialist mechanic on speed dial.
Most Expensive Failure
M275.950 (S 600, facelift) — twin‑turbo and cooling system
“The biturbo V12 is complex and costly to maintain. Turbocharger failure, cooling system leaks, and ignition coil issues are all common — and all expensive to repair.”
Who it's for: buyers who want V12 flagship status and can afford the premium running costs.
Best Value
OM648.960 (S 320 CDI)
“The facelift diesel offers the best balance of performance, economy (up to 34 mpg), and reliability. It's the sweet spot in the W220 range.”
Who it's for: high‑mileage drivers and those who want S‑Class luxury without V12 running costs.
Most Overlooked
M113.986 (S 55 AMG)
“The supercharged 5.4‑litre V8 delivers 360 bhp with genuine AMG performance. It's often overlooked in favour of the V12 models but offers a more reliable and engaging driving experience.”
Who it's for: buyers who want AMG performance without the V12's reliability headaches.
Mercedes S-Class W220 — Ownership Economics
The W220 rule
A £2,200–£4,500 OM648 recon against a £3,000–£10,000 W220 sits at 22–150% of the car's value. On a sub‑£4,000 W220, that approaches or exceeds our 70% Mercedes threshold — we'll honestly tell you to walk away. Against a well‑kept £8,000+ example, the same recon drops to a routine 28–56% — a repair decision, not a financial one. The V12 cars are a different proposition entirely — their replacement costs often exceed the vehicle's value.
Key Takeaways
Which W220 Costs Least To Own?
S 320 CDI (OM648) — best balance of economy and reliability.
Which W220 Costs Most To Own?
S 600 (M137/M275) — V12 running costs are astronomical.
Which W220 Is Best Value?
S 320 CDI (OM648) — the sweet spot in the range.
Common Problems
W220 Engine Replacement Costs — By Engine and Condition
No Generation variance from the Model Page's baseline figures — the W220 shares its platform with the C215 CL‑Class, so engine‑bay access and labour times are consistent across the range. Costs are inherited directly per the Authority Model, with no divergence note required.
Core Variants
Core Variants
Scope note: All variants listed are W220 saloon only. The C215 CL‑Class shares most of these engines but is covered on its own Generation Page, since fitment and labour access vary slightly by body style.
Market Intelligence
Most Requested E90 Engines (2025)
- 1.1. OM648 (3.2 straight‑six diesel) — most‑requested diesel in the W220 range
- 2.2. M113 (V8 petrol) — strong demand for the S 500
- 3.3. M275 (V12 biturbo) — niche enthusiast demand for the facelift S 600
Most Requested E90 Variants
- 1.1. S 320 CDI
- 2.2. S 500
- 3.3. S 55 AMG
Average E90 Replacement Cost
£1,800–£12,000 supply only [MB‑QUOTE]
Most Common E90 Failures
- 1.1. M137 V12 cylinder wall deformation (S 600/S 63 AMG)
- 2.2. OM613 injector/EGR failure (pre‑facelift diesel)
- 3.3. M113 V8 oil leaks
Mercedes S 320 CDI W220 (OM648)
4
enquiries
Mercedes S 500 W220 (M113)
3
enquiries
Mercedes S 600 W220 (M137)
2
enquiries
FAQ
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