Mercedes SL (1999)

Estimated running costs and MOT pass rates from 1,617 MOT tests in 2024.

Annual Cost

£2,738

£228/month

MOT Pass Rate

87%

Good

Road Tax

£375

Estimated/year

Est. Insurance

Grp 35-50

4973cc Petrol

Solid Option

87% pass rate, £2,738/year to run. 5 points above average.

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Petrol4973cc27 years old1,617 tests85k miles avg

Annual Running Costs

Fuel (Petrol, 4973cc)

~30 mpg

£1,958

Road Tax

Pre-2001 engine size rate

£375

MOT Test

£55

Predicted Repairs

£350

Total per year£2,738

Per month£228/mo

Per week£53/wk

Estimates based on 7,400 miles/year (UK average), petrol at 174.57p a litre (GOV.UK weekly average, week of 19 October 2026), GOV.UK road tax rates and repair likelihood from MOT data. Insurance not included.

Reliability Verdict

87% MOT pass rate(Good)

0%All-model avg: 82%100%

Good reliability. Occasional issues but generally solid. That's close to the average of 82% across all models in our data.

87% of MOT tests on Mercedes SLs from 1999 ended in a pass in 2024, when they were about 25 years old. That's based on 1,617 tests across the UK, retests included. The average mileage recorded at those tests was 84,924 miles.

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How Does It Compare?

Rank among 1999 models48th of 361(top 14%)

Rank among Mercedes models797th of 1,376(bottom half)

vs average of all models+5%(82% avg)

vs 1999 models average+12%(75% avg)

vs Mercedes average+0%(87% avg)

Mileage Analysis

84,924

Average miles

185,000

Expected for age

The average 1999 Mercedes SL had 84,924 miles on the clock at its 2024 MOT, which is significantly below the expected 185,000 miles for a 25-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?

Of the years with at least 100 tests, the 2019 model has the highest MOT pass rate at 97%, while the 1990 model has the lowest at 81%. The 1999 scores 87%. Newer cars usually pass more often simply because they are younger, so compare years of a similar age.

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

Mercedes CLK

2000 · 5439cc Petrol

£2,738/year

81%

-6%

TVR Chimaera

1999 · 4546cc Petrol

£2,738/year

88%

+1%

Toyota Land Cruiser

1998 · 4477cc Petrol

£2,888/year

78%

-9%

Mercedes ML

2001 · 4966cc Petrol

£3,303/year

77%

-10%

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About the 1999 Mercedes SL

The 1999 Mercedes SL is a premium performance car. Our records list a 4973cc petrol engine, though engines vary between versions. 1,617 MOT tests were recorded on this model in 2024, making it a reasonably common sight on UK roads. It ranks in the top 14% of all 1999 models for MOT pass rate.

With an average of 84,924 miles recorded at its 2024 MOT tests, 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.

1999 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 £1,958 per year with petrol at 174.57p per litre (GOV.UK weekly average, week of 19 October 2026; based on 7,400 miles per year).

What does it cost to own a 1999 Mercedes SL?

Total estimated annual running cost is £2,738 (£228/month), broken down as £1,958 fuel, £375 road tax, £55 MOT, and £350 predicted repairs. Repair costs are moderate, reflecting the 87% pass rate. Keeping on top of servicing will help avoid surprises.

Mercedes SL Reliability Trend

Newer Mercedes SLs pass their MOT more often than older ones, by 4 percentage points on average, which is mostly down to age and wear.

Buying a Used 1999 Mercedes SL

At 27 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

These are typical issues for cars of this age, fuel type and engine size, not faults recorded on this model's MOT tests. Use them as a checklist when you view one.

Timing Chain / Belt

Watch out

At 27 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.

Clutch Wear

Medium risk

With an average of 85k miles, clutch replacement may be due (typical lifespan 60,000-100,000 miles). Budget £400-£800 for a new clutch kit.

Brake Discs and Pads

Medium risk

High-mileage cars often need brake disc replacement, not just pads. A full set of discs and pads costs £200-£500 per axle.

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 1999 Mercedes SL stacks up against similar cars for estimated annual running costs, insurance group, and tax.

Car	Pass Rate	Fuel/yr	Tax/yr	Est. Ins. Group	Total/yr
Mercedes SL(1999)	87%	£1,958	£375	Grp 35-50	£2,738
Mercedes CLK(2000)	81%	£1,958	£375	Grp 35-50	£2,738same
TVR Chimaera(1999)	88%	£1,958	£375	Grp 35-50	£2,738same
Toyota Land Cruiser(1998)	78%	£1,958	£375	Grp 35-50	£2,888+£150
Mercedes ML(2001)	77%	£1,958	£790	Grp 35-50	£3,303+£565

Estimates based on 7,400 miles/year, GOV.UK average pump prices for the week of 19 October 2026, GOV.UK road tax rates and MOT data. Insurance groups are our rough estimate from engine size, not official groups. Actual costs vary by driver, location, and usage.

Questions about the 1999 Mercedes SL

Is the 1999 Mercedes SL reliable?

Good reliability. Occasional issues but generally solid. 87% of MOT tests on 1999 Mercedes SLs ended in a pass, from 1,617 tests (DVSA MOT data for tests in 2024, retests included). That's 5 points above the average of 82% across all models in the same data.

How much does a 1999 Mercedes SL cost to run?

Our estimate is £2,738 a year (£228 a month): £1,958 fuel, £375 road tax, £55 MOT and £350 predicted repairs, based on 7,400 miles a year. Insurance is not included.

What is the MOT pass rate for a 1999 Mercedes SL?

87% of 1,617 MOT tests on the 1999 Mercedes SL ended in a pass (DVSA MOT data for tests in 2024, retests included). That ranks it 48th of 361 models first registered in 1999 (top 14%).

Which year Mercedes SL has the best MOT pass rate?

Of the years with at least 100 tests, the 2019 Mercedes SL has the highest MOT pass rate at 97% and the 1990 the lowest at 81%. Newer cars usually pass more often simply because they are younger and have done fewer miles.

What is the average mileage for a 1999 Mercedes SL?

The average mileage recorded at MOT tests on the 1999 Mercedes SL is 84,924 miles, which is significantly below the expected 185,000 miles for a 25-year-old car. Low-mileage examples may have spent time sitting unused, so check for issues like corroded brakes or perished rubber seals.