M274 vs M270 — Which Should You Buy?

The M274 wins for most buyers — it's more refined, more efficient and generally more reliable than the earlier M270. The M274 is the more modern, more advanced engine and is used in newer, more desirable Mercedes models. The M270 is a proven engine but its age means higher running costs and a higher probability of expensive repairs.

M270 (2.0L turbo petrol): 150 enquiries in 2025 [EM-VERIFIED], typical reconditioned engine cost £1,500–£2,800 [EM-QUOTE], 181–208 bhp, known for timing chain stretch and carbon build-up
M274 (2.0L turbo petrol): 130 enquiries in 2025 [EM-VERIFIED], typical reconditioned engine cost £2,000–£3,800 [EM-QUOTE], 181–241 bhp, known for timing chain tensioner and water pump issues
M274 delivers better fuel economy (38–42 mpg vs 35–39 mpg) and lower CO₂ emissions
M270's timing chain stretch can be catastrophic; M274's tensioner issues are generally less severe
M274 is used in newer C‑Class, E‑Class, GLC and GLE models, with better parts support

Full spec comparison, five‑year ownership cost analysis, and a clear verdict for your budget and driving needs below.

At a Glance

	M270 (2.0L Turbo)	M274 (2.0L Turbo)
2025 UK Enquiries	150 [EM-VERIFIED]	130 [EM-VERIFIED]
Displacement	2.0L turbo petrol	2.0L turbo petrol
Power Output	181–208 bhp	181–241 bhp
Recon Engine Supply & Fit	£1,500–£2,800	£2,000–£3,800
Typical Real‑World MPG	35–39	38–42
Defining Failure Points	Timing chain stretch, carbon build-up, fuel injector failure	Timing chain tensioner, water pump failure, carbon build-up
Best For	Budget‑conscious buyers, older A/CLA/GLA models	Modern performance, better efficiency, newer C/E/GLC models

The Verdict

The M274 is the better engine for the vast majority of buyers. It's more powerful (in most variants), more fuel‑efficient, more refined and used in newer, more desirable Mercedes models. The M270 is an older design with known timing chain stretch issues that can be catastrophic. While the M270's lower entry price is appealing, the M274's superior reliability and efficiency make it a better long‑term investment. Unless you're specifically chasing the older engine's character or are on a very tight budget, the M274 is the clear winner.

M270 — The Proven Turbo Four

The M270 is Mercedes' 2.0‑litre turbo petrol engine, produced from 2011 to 2019. It was used across the compact range: A‑Class (W176), B‑Class (W246), CLA (C117), GLA (X156) and GLC (X253). It produces 181–208 bhp and is known for its punchy performance and decent fuel economy. The engine's biggest weakness is timing chain stretch — the chain can stretch and cause timing issues, leading to poor running and, in severe cases, catastrophic engine failure. Carbon build‑up on intake valves (due to direct injection) and fuel injector failures are also known issues. Replacement cost for a reconditioned unit is £1,500–£2,800 [EM‑QUOTE], making it relatively affordable to replace. It's an engine that can still be a good buy if you find one with the timing chain already addressed. See our M270 Knowledge Centre for more detail.

M274 — The Evolved Turbo Four

The M274 is Mercedes' 2.0‑litre turbo petrol engine, introduced in 2013 and used until 2021. It's a significant evolution of the four‑cylinder concept, with better fuel economy, lower emissions and improved refinement. The M274 is used in the C‑Class (W205), E‑Class (W213), GLC (X253), GLE (W166) and SLC (R172). Power outputs range from 181 to 241 bhp depending on the variant. The M274 is more fuel‑efficient (38–42 mpg vs 35–39 mpg) and has lower CO₂ emissions than the M270. Known issues include timing chain tensioner wear (especially on earlier models), water pump failure, and carbon build‑up on intake valves. These issues are generally less severe than the M270's timing chain stretch problem. Replacement cost is slightly higher at £2,000–£3,800 [EM‑QUOTE], reflecting the engine's newer design and higher parts costs. The M274 is the engine to choose if you want modern performance, refinement and lower running costs. Our M274 Knowledge Centre has full specs and fitment details.

Cost & Ownership Comparison

The M274 is cheaper to run than the M270 over a typical five‑year period, despite similar purchase prices for comparable models. The M274's better fuel economy saves around £200–£400 per year in fuel costs, and its superior reliability (fewer catastrophic failure modes) means fewer unexpected repair bills. The M270's lower entry price on older models is tempting, but the risk of timing chain stretch (costing £1,500–£3,000 to fix) can quickly erode any upfront saving. Over 50,000 miles, the M274 typically costs its owner £1,000–£2,000 less to run than the M270, making it the more financially sensible choice in the long run. For those on a tight budget, a well‑maintained M270 with documented timing chain work can still be a good option.

Metric (5 yrs, 50k miles)	M270 (2.0L)	M274 (2.0L)
Fuel cost	£6,500–£7,200	£5,800–£6,400
Servicing (scheduled)	£1,000–£1,400	£900–£1,300
Tax (VED)	£800–£1,000	£700–£900
Insurance (estimated)	£2,000–£2,800	£2,200–£3,000
Total estimated	£10,300–£12,400	£9,600–£11,600

These figures are [ESTIMATED] based on UK market data and our proprietary enquiry patterns. Actual costs vary by driving style, location and individual vehicle condition.

Which Should You Buy?

💰

Best Value & Lower Entry Price

M270 — older A‑Class, CLA and GLA models are significantly cheaper to buy. Just budget for timing chain work (if not already done) and factor in higher running costs.

🚗

Modern Performance & Efficiency

M274 — more powerful (in most variants), more efficient and more reliable. Used in newer, more desirable models like the W205 C‑Class and W213 E‑Class.

🔧

Simpler Maintenance & Lower Risk

M274 — fewer catastrophic failure modes, better engineering and more modern technology. Lower probability of a major repair.

🎵

Character & Traditional Turbo Feel

M270 — some enthusiasts prefer the more old‑school turbo character of the earlier engine. If that's your priority, the M270 has charm the M274 can't match.

Whichever you choose, our repair vs replace calculator can help you decide what to do if you face a major engine failure.

Other Four‑Cylinder Comparisons

If you're still weighing up your options, these comparisons cover related Mercedes petrol engines.

M274 vs M270 →

You're here — 2.0L turbo generations.

Diesel vs Petrol Running Costs →

Which fuel type suits your mileage?

M272 vs M276 →

V6 petrol comparison.

A‑Class vs CLA →

Compact models compared.

For more detailed engine‑specific information, visit our M270 Knowledge Centre or M274 Knowledge Centre.

Frequently Asked Questions

Which four‑cylinder is more reliable, M270 or M274?

The M274 is more reliable. The M270 suffers from timing chain stretch that can be catastrophic. The M274's timing chain tensioner issues are generally less severe and easier to catch early.

Which is cheaper to run, M270 or M274?

The M274 is cheaper to run — it uses less fuel (38–42 mpg vs 35–39 mpg) and has lower servicing costs. The M270's lower purchase price is offset by higher fuel bills and the risk of timing chain repairs.

Which has more tuning potential, M270 or M274?

Both have strong tuning potential, but the M274's more advanced engine management and turbocharger design make it easier to extract reliable power. Up to 300 bhp is achievable with a remap and hardware upgrades.

Can I fit an M274 into an older Mercedes?

No — the engine mounts, ECU, gearbox and cooling systems are completely different. An engine swap between generations is not practical or cost‑effective.

Is the M274 timing chain issue as bad as the M270?

No — the M274 timing chain tensioner wear is generally less severe, more predictable and easier to catch early. The M270 timing chain stretch can happen suddenly and without warning, often destroying the engine.

✓

280 Combined EnquiriesM270 and M274 analysed from real 2025 UK data.

✓

A Real VerdictWe name a winner for most buyers, and explain when the M270 still makes sense.

✓

15+ Vetted Mercedes SpecialistsExperienced with both four‑cylinder petrol engines.

✓

100% IndependentNo sponsors, no manufacturer influence.