Used car guide

1991 Mercedes-Benz SL: common problems and MOT failures

What MOT testers find on the Mercedes-Benz SL first registered in 1991: we looked at the 322 MOTs these cars had during 2023–2025. Plus known faults and what to look at before you buy one.

Small sample: there were only 322 MOTs of these cars during 2023–2025, so treat the percentages as rough. The known faults below don't depend on it.

322MOTs of 1991 cars, done in 2023–2025
80%pass first time (all 1991 cars: 71%)
2,600typical miles a year
21%had suspension flagged

Common 1991 Mercedes-Benz SL MOT failures and advisories

The share of 1991 Mercedes-Benz SL MOT tests where testers flagged each area, as a fail or an advisory. Rough prices are typical independent-garage costs.

  • Suspension
    21% of testsRough price £120–£400

    At the viewing: Listen for knocks over speed bumps, and look behind each front wheel for a snapped coil spring.

  • Brakes
    19% of testsRough price £150–£350

    At the viewing: Look for a lip on the disc edges and feel for judder or pulling when braking firmly from about 40mph.

  • Lights and electrics
    18% of testsRough price £10–£80

    At the viewing: Ask a friend to check every light, including brake lights and indicators, while you operate them.

  • Oil and fluid leaks
    13% of testsRough price £80–£600

    At the viewing: Look under the engine and on the ground where the car is usually parked for fresh oil or fluid.

  • Tyres
    9% of testsRough price £70–£150

    At the viewing: Check the tread on all four tyres, including the inside edges, and look for cracks or bulges.

  • Exhaust and emissions
    7% of testsRough price £100–£1,200

    At the viewing: Look for black soot in the tailpipe, listen for blowing from the exhaust and check for engine or DPF warning lights.

Questions to ask the seller before buying a 1991 Mercedes-Benz SL

Ask before you travel to see it. A seller who knows the car will have answers, and receipts.

  1. Can I see the service history and receipts for any big jobs?

Looking at a Mercedes-Benz SL?

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Other years

Every year of the Mercedes-Benz SL compared

YearMOT testsMost flagged
2021–Too few tests
2020340Tyres 16%
20191,021Tyres 19%
20181,199Tyres 20%
20171,909Tyres 23%
20162,304Tyres 21%
20152,389Tyres 22%
20143,166Tyres 22%
20133,382Tyres 22%
20121,246Tyres 21%
2011753Tyres 22%
20101,052Tyres 25%
20091,418Tyres 24%
20082,265Brakes 24%
20072,348Brakes 22%
20062,390Brakes 26%
20053,344Brakes 23%
20045,466Brakes 24%
20037,027Suspension 24%
20022,895Brakes 26%
2001855Brakes 21%
20001,444Suspension 28%
19991,608Suspension 29%
19982,055Suspension 26%
19971,994Brakes 26%
19961,742Brakes 26%
19951,614Brakes 24%
19941,166Suspension 26%
1993476Brakes 24%
1992351Suspension 23%
1990208Brakes 22%

Where this comes from: the DVSA's anonymised results for every MOT test done in Great Britain during 2023–2025, counting the MOTs of Mercedes-Benz SL cars first registered in 1991. "Flagged" includes advisories, so it isn't the same as a fail rate. How we score