BMW
M6
Mercedes-Benz
CL
BMW M6 vs Mercedes-Benz CL: 2015 Comparison
The short answer
The BMW M6 offers fuel economy, while the Mercedes-Benz CL excels at power instead. Choose the BMW M6 if you prioritize fuel economy in daily driving, or the Mercedes-Benz CL if power matters more for your needs. Both are covered by real owner reports on CarWizz.
Specs side by side
What owners say
M6
Overall
Sentiment is deeply polarized and highly conditional. The vehicle is universally revered for its high-revving 5.0L V10 (S85) engine, described as an "insanely fast" and "brilliant" powerplant above 5,000 RPM, offering a unique and thrilling driving experience that creates significant owner pride and excitement. However, this is heavily counterbalanced by very frequent and severe criticism regarding legendary reliability concerns and extreme ownership costs.
Best version to buy
Insufficient owner data available to designate a specific model year or trim (e.g., Competition Package) as the "best." The primary differentiator discussed is transmission choice. The 6-speed manual (6MT) is highly prized for its rarity, driver engagement, and because it avoids the notorious reliability issues of the SMG III automated manual transmission.
Known issues
- ⚠Rod bearing failures in the S85 V10 engine: considered a critical, well-documented flaw requiring preventative replacement; catastrophic engine failure risk. Frequency: very frequent.
- ⚠SMG III transmission reliability: prone to major failures, expensive repairs, and criticized for poor drivability in daily use. Frequency: very frequent.
- ⚠Throttle actuator failures: another common and expensive fault with the S85 engine. Frequency: very frequent.
CL
Overall
Owner sentiment is highly conditional, centered on the significant and well-documented maintenance costs associated with the complex Active Body Control (ABC) hydraulic suspension system. The vehicle is universally praised for its timeless design, luxurious feel, and potent V8/V12 engines, offering an exceptional driving experience when fully functional. However, the consensus is that ownership is a high-risk, high-reward proposition, suitable only for those with substantial maintenance budgets and access to specialized independent mechanics.
Best version to buy
Insufficient owner data available to designate a single "best" version. Discussions indicate a trade-off: earlier models (pre-2003) are noted to have first-generation ABC components with known issues, while later facelift models (2003+) may have addressed some of these problems.
Known issues
- ⚠Active Body Control (ABC) hydraulic suspension failures: includes leaking struts, failing accumulators (spheres), valve block issues, and pump failures. Very expensive to repair, with full system replacement sometimes required.
- ⚠High general maintenance and repair costs: attributed to the car's complex technology and luxury status. Electronics, plastic engine bay components, and other wear items are costly. Frequency: very frequent.
- ⚠Engine-specific concerns (varies by model year and engine): for 2007+ models (C216 generation, M273 V8), balance shaft sprocket/chain wear leading to potential engine failure is noted as a major issue.
The verdict
The BMW M6 is the better choice for most buyers.
It has better fuel economy on its best-equipped version than the Mercedes-Benz CL, based on the data above. If power matters more to you than running costs, the Mercedes-Benz CL is worth a closer look instead.
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Frequently asked questions
Which is more reliable, the BMW M6 or the Mercedes-Benz CL?
Owner reports show similar reliability sentiment for the BMW M6 and the Mercedes-Benz CL. Check the known issues listed above for specific differences between the two.
Which is better for families, the BMW M6 or the Mercedes-Benz CL?
The BMW M6 seats more passengers than the Mercedes-Benz CL on its catalogued best-equipped version. Body type also differs: the BMW M6 is classed as a Sedan, the Mercedes-Benz CL as a Coupe.
Which has better fuel economy, the BMW M6 or the Mercedes-Benz CL?
The BMW M6 is more fuel-efficient on paper: 10.3 L/100km combined versus 14.3 L/100km for the Mercedes-Benz CL, based on the best-equipped catalogued version of each.
Which is cheaper to maintain, the BMW M6 or the Mercedes-Benz CL?
Exact maintenance costs aren't in our data, but owner reports mention cost-related concerns more often for the Mercedes-Benz CL than the BMW M6. See the known issues comparison above.