How much does a 1991 MERCEDES SL cost to run?

Estimated annual running cost is £2,757 (£230/month), including £1592 fuel, £760 road tax, £55 MOT, and £350 predicted repairs.

What is the MOT pass rate for a 1991 MERCEDES SL?

The 1991 MERCEDES SL has a 86% MOT pass rate based on 288 tests in 2026. This ranks 51 out of 179 cars from 1991.

Which year MERCEDES SL is most reliable?

The 2019 MERCEDES SL has the highest MOT pass rate at 97%. The least reliable year is 1990 at 81%.

MERCEDES SL (1991)

Q: Is the 1991 MERCEDES SL reliable?

Good reliability. Occasional issues but generally solid. 86% of MERCEDES SLs from 1991 passed their MOT first time in 2026, based on 288 tests. That's 4 points above the national average of 82%.

Q: What is the average mileage for a 1991 MERCEDES SL?

The average mileage for a 1991 MERCEDES SL is 78,703 miles, which is significantly below the expected 259,000 miles for a 35-year-old car. Low-mileage examples may have spent time sitting unused, so check for issues like corroded brakes or perished rubber seals.

Running costs, reliability data, and common problems from 288 real MOT tests.

Annual Cost

£2,757

£230/month

MOT Pass Rate

86%

Good

Road Tax

£760

Based on CC/year

Insurance

Grp 35-50

4973cc Petrol

Solid Option

86% pass rate, £2757/year to run. Close to the national average.

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Petrol4973cc35 years old288 tests79k miles avg

Annual Running Costs

Fuel (Petrol, 4973cc)

~30 mpg

£1,592

Road Tax

Based on 4973cc

£760

MOT Test

£55

Predicted Repairs

£350

Total per year£2,757

Per month£230/mo

Per week£53/wk

Based on 7,400 miles/year (UK average), current fuel prices, and repair likelihood from MOT data. Insurance not included.

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Reliability Verdict

86% MOT pass rate(Good)

0%National avg: 82%100%

Good reliability. Occasional issues but generally solid. That's close to the national average of 82%.

At 35 years old, 86% of MERCEDES SLs from 1991 passed their MOT first time in 2026. That's based on 288 tests across the UK. The average mileage at this age is 78,703 miles.

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How Does It Compare?

Rank among 1991 cars51th of 179(top 28%)

Rank among MERCEDES models865th of 1,408(top 61%)

vs national average+4%(82% avg)

vs 1991 cars average+8%(78% avg)

vs MERCEDES average-1%(87% avg)

Mileage Analysis

78,703

Average miles

259,000

Expected for age

The average 1991 MERCEDES SL has 78,703 miles on the clock, which is significantly below the expected 259,000 miles for a 35-year-old car. Low-mileage examples may have spent time sitting unused, so check for issues like corroded brakes or perished rubber seals.

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Best Year to Buy?

The most reliable year is the 2019 model with a 97% MOT pass rate, while the 1990 model has the lowest at 81%. The 1991 sits between the two at 86%.

MERCEDES SL by Year

Year	Pass Rate	Tests	Avg Mileage
2019	97%	851	19,987 mi
2018	93%	1,022	25,750 mi
2017	94%	1,847	30,630 mi
2016	95%	2,240	36,109 mi
2015	92%	2,222	40,591 mi
2014	92%	2,892	47,357 mi
2013	89%	2,796	49,450 mi
2012	90%	1,136	50,476 mi
2011	92%	579	50,602 mi
2010	88%	955	62,402 mi
2009	87%	1,222	63,020 mi
2008	90%	1,940	65,610 mi
2007	88%	1,792	71,215 mi
2006	87%	1,832	73,640 mi
2005	88%	2,430	75,394 mi
2004	88%	4,036	77,676 mi
2003	86%	5,173	75,808 mi
2002	88%	2,083	74,421 mi
2001	90%	528	78,534 mi
2000	86%	955	84,195 mi
1999	87%	1,617	84,924 mi
1998	86%	2,018	89,595 mi
1997	87%	2,117	93,418 mi
1996	88%	1,778	93,971 mi
1995	85%	1,627	99,248 mi
1994	88%	1,244	93,271 mi
1993	88%	462	85,167 mi
1992	87%	312	90,571 mi
1991	86%	288	78,703 mi
1990	81%	186	88,429 mi

Similar Cars to Consider

JAGUAR XJS

1990 · 5343cc Petrol

£2,247/year

82%

-4%

MERCEDES 500

1991 · 4973cc Petrol

£2,247/year

87%

+1%

JAGUAR XJ

1990 · 5345cc Petrol

£2,247/year

86%

same

PORSCHE 928 S

1991 · 4957cc Petrol

£2,247/year

81%

-5%

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About the 1991 MERCEDES SL

The 1991 MERCEDES SL is a performance with a 4973cc petrol engine. 288 of these vehicles were MOT tested in 2026, making it a less common model in the UK market. Among all cars from 1991, the average MOT pass rate is 78%, and this model beats that benchmark.

With an average of 78,703 miles at 35 years old, MERCEDES SL owners tend to use this car less than the typical driver. Very low mileage could mean the car has been garaged or used only for short trips, which can cause its own issues like battery drain and moisture buildup.

1991 MERCEDES SL Fuel Costs

The 4973cc petrol engine is on the larger side, so fuel won't be this car's strong point. Expect around 30 mpg in mixed driving, which works out to roughly £1,592 per year at current petrol prices of 142p per litre (based on 7,400 miles per year).

What does it cost to own a 1991 MERCEDES SL?

Total estimated annual running cost is £2,757 (£230/month), broken down as £1592 fuel, £760 road tax, £55 MOT, and £350 predicted repairs. Repair costs are moderate, reflecting the 86% pass rate. Keeping on top of servicing will help avoid surprises.

MERCEDES SL Reliability Trend

Newer MERCEDES SLs show better MOT pass rates than older ones, with an average improvement of 4 percentage points.

Buying a Used 1991 MERCEDES SL

At 35 years old, the MERCEDES SL is firmly in budget territory. Purchase prices are low, but check for rust, worn suspension bushes, and electrical gremlins. A full service history is especially valuable at this age. If you're flexible on year, the 2019 model has the highest pass rate at 97%.

Common Issues to Watch For

Based on the 1991 MERCEDES SL's fuel type, age, and engine size, these are the most likely problem areas to check.

Timing Chain / Belt

Watch out

At 35 years old, check whether the timing belt has been replaced (typically due every 5-7 years or 60,000-100,000 miles). A snapped belt can destroy the engine.

Oil Consumption

Medium risk

Larger petrol engines can develop higher oil consumption as they age. Check the oil level and look for blue smoke from the exhaust.

Rust and Corrosion

Watch out

At 10+ years, check wheel arches, sills, subframe, and brake lines for rust. Structural corrosion is an MOT failure. Prevention is far cheaper than repair.

Suspension Bushings

Watch out

Rubber suspension bushes harden and crack with age, causing knocking noises and vague handling. A full refresh costs £300-£800 depending on the car.

Service History

Low risk

Always request a full service history. Regular servicing is the single best indicator of how well a car has been maintained, regardless of mileage.

Running Costs Compared

How the 1991 MERCEDES SL stacks up against similar cars for annual running costs, insurance, and tax.

Car	Pass Rate	Fuel/yr	Tax/yr	Insurance	Total/yr
MERCEDES SL(1991)	86%	£1592	£760	Grp 35-50	£2757
JAGUAR XJS(1990)	82%	£1592	£250	Grp 35-50	£2247-£510
MERCEDES 500(1991)	87%	£1592	£250	Grp 35-50	£2247-£510
JAGUAR XJ(1990)	86%	£1592	£250	Grp 35-50	£2247-£510
PORSCHE 928 S(1991)	81%	£1592	£250	Grp 35-50	£2247-£510

Estimates based on 7,400 miles/year, current fuel prices, and MOT data. Insurance groups are indicative. Actual costs vary by driver, location, and usage.