Mercedes CLS vs Porsche 911

Both are coupés & GTs. First-time MOT failure at age 7, and what each one is known to fail on.

The Porsche 911 is the more reliable of the two. It fails its first MOT at age 7 5.7% of the time, against 18.2% for the Mercedes CLS.

Mercedes CLS

18.2%

fail at age 7

Rank 115 of 239 · 64k miles at 7 · 17,327 tests

Porsche 911

5.7%

fail at age 7

Rank 3 of 239 · 24k miles at 7 · 22,079 tests

What each one fails on

Measured

The faults each records most at ages 6 to 9. Same figures as each full report.

A wheel bearing with excessive playAdvisory4.7%

A suspension pin, bush or joint excessively wornAdvisory4.0%

A suspension joint dust cover severely deterioratedMinor3.0%

A spring or spring component fractured or seriously weakenedFail2.6%

A wheel badly distorted or wear between wheel and hub at spigot mountingAdvisory1.8%

Engine MIL illuminated indicating a malfunctionFail1.7%

Brake pipe damaged or excessively corrodedAdvisory0.7%

Fluid leaking excessively and likely to harm the environment or to pose a safety risk to other road usersAdvisory0.6%

A suspension pin, bush or joint excessively wornAdvisory0.5%

A spring or spring component fractured or seriously weakenedAdvisory0.4%

Coolant leakAdvisory0.4%

A shock absorber damaged to the extent that it does not function or showing signs of severe leakageAdvisory0.3%