Mercedes SLK (2012)

Estimated running costs and MOT pass rates from 13,361 MOT tests in 2024.

Annual Cost

£2,491

£208/month

MOT Pass Rate

84%

Good

Road Tax

£410

Estimated/year

Est. Insurance

Grp 25-38

2500cc Diesel

Solid Option

84% pass rate, £2,491/year to run. Close to the average across all models.

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Diesel2500cc14 years old13,361 tests65k miles avg

Annual Running Costs

Fuel (Diesel, 2500cc)

~40 mpg

£1,676

Road Tax

Estimated CO2 band

£410

MOT Test

£55

Predicted Repairs

£350

Total per year£2,491

Per month£208/mo

Per week£48/wk

Estimates based on 7,400 miles/year (UK average), diesel at 199.33p 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

84% 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.

84% of MOT tests on Mercedes SLKs from 2012 ended in a pass in 2024, when they were about 12 years old. That's based on 13,361 tests across the UK, retests included. The average mileage recorded at those tests was 64,940 miles.

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How Does It Compare?

Rank among 2012 models264th of 650(top half)

Rank among Mercedes models919th of 1,376(bottom half)

vs average of all models+2%(82% avg)

vs 2012 models average+6%(78% avg)

vs Mercedes average-3%(87% avg)

Mileage Analysis

64,940

Average miles

88,800

Expected for age

The average 2012 Mercedes SLK had 64,940 miles on the clock at its 2024 MOT, which is below the expected 88,800 miles for a 12-year-old car. This suggests lighter use than average, which generally means less wear on major components.

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Best Year to Buy?

Of the years with at least 100 tests, the 2016 model has the highest MOT pass rate at 89%, while the 1996 model has the lowest at 76%. The 2012 scores 84%. Newer cars usually pass more often simply because they are younger, so compare years of a similar age.

Mercedes SLK by Year

Year	Pass Rate	Tests	Avg Mileage
2016	89%	2,572	42,977 mi
2015	87%	11,055	48,710 mi
2014	87%	11,284	55,581 mi
2013	85%	11,106	62,322 mi
2012	84%	13,361	64,940 mi
2011	85%	5,660	61,469 mi
2010	80%	4,472	66,541 mi
2009	81%	5,347	71,532 mi
2008	80%	6,876	75,187 mi
2007	79%	7,700	77,695 mi
2006	79%	7,884	80,213 mi
2005	78%	10,305	82,791 mi
2004	78%	6,598	84,132 mi
2003	78%	3,327	85,438 mi
2002	81%	3,692	87,295 mi
2001	82%	4,005	90,848 mi
2000	79%	3,545	90,918 mi
1999	79%	4,295	87,626 mi
1998	79%	3,523	89,671 mi
1997	81%	2,190	90,802 mi
1996	76%	126	98,709 mi

Similar Cars to Consider

BMW 3 Series

2012 · 2000cc Diesel

£2,077/year

82%

-2%

Mercedes E

2014 · 2143cc Diesel

£2,491/year

84%

same

Land Rover Range Rover Evoque

2014 · 2200cc Diesel

£2,491/year

88%

+4%

Honda Civic

2010 · 2204cc Diesel

£2,641/year

75%

-9%

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About the 2012 Mercedes SLK

The 2012 Mercedes SLK is a premium car. Our records list a 2500cc diesel engine, though engines vary between versions. 13,361 MOT tests were recorded on this model in 2024, making it one of the most commonly tested models on UK roads. Among all models from 2012, the average MOT pass rate is 78%, and this model beats that benchmark.

With an average of 64,940 miles recorded at its 2024 MOT tests, Mercedes SLK owners tend to use this car less than the typical driver.

2012 Mercedes SLK Fuel Costs

The 2500cc diesel engine is on the larger side, so fuel won't be this car's strong point. Expect around 40 mpg in mixed driving, which works out to roughly £1,676 per year with diesel at 199.33p per litre (GOV.UK weekly average, week of 19 October 2026; based on 7,400 miles per year). Diesel cars of this age should have their DPF (diesel particulate filter) checked, as replacements can be costly.

What does it cost to own a 2012 Mercedes SLK?

Total estimated annual running cost is £2,491 (£208/month), broken down as £1,676 fuel, £410 road tax, £55 MOT, and £350 predicted repairs. Repair costs are moderate, reflecting the 84% pass rate. Keeping on top of servicing will help avoid surprises.

Mercedes SLK Reliability Trend

Newer Mercedes SLKs 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 2012 Mercedes SLK

At 14 years old, the Mercedes SLK 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 2016 model has the highest pass rate at 89%. With 13,361 MOT tests in our data, there's strong statistical confidence in these figures.

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.

DPF (Diesel Particulate Filter)

Watch out

Short journeys clog the DPF. Replacement costs £1,000-£2,500. Check the DPF warning light and ask about driving patterns.

Turbo Wear

Watch out

Diesel turbos work harder and wear faster. Listen for whining noises and check for oil leaks around the turbo housing.

EGR Valve

Watch out

Exhaust Gas Recirculation valves clog with carbon deposits, causing rough running and poor economy. Cleaning costs £150-£300, replacement £300-£600.

Dual Mass Flywheel

Watch out

Larger diesel engines put extra strain on the dual mass flywheel. Listen for rattling at idle. Replacement with clutch is £800-£1,500.

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 2012 Mercedes SLK 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 SLK(2012)	84%	£1,676	£410	Grp 25-38	£2,491
BMW 3 Series(2012)	82%	£1,397	£275	Grp 18-32	£2,077-£414
Mercedes E(2014)	84%	£1,676	£410	Grp 25-38	£2,491same
Land Rover Range Rover Evoque(2014)	88%	£1,676	£410	Grp 25-38	£2,491same
Honda Civic(2010)	75%	£1,676	£410	Grp 25-38	£2,641+£150

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 2012 Mercedes SLK

Is the 2012 Mercedes SLK reliable?

Good reliability. Occasional issues but generally solid. 84% of MOT tests on 2012 Mercedes SLKs ended in a pass, from 13,361 tests (DVSA MOT data for tests in 2024, retests included). That's 2 points above the average of 82% across all models in the same data.

How much does a 2012 Mercedes SLK cost to run?

Our estimate is £2,491 a year (£208 a month): £1,676 fuel, £410 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 2012 Mercedes SLK?

84% of 13,361 MOT tests on the 2012 Mercedes SLK ended in a pass (DVSA MOT data for tests in 2024, retests included). That ranks it 264th of 650 models first registered in 2012 (top half).

Which year Mercedes SLK has the best MOT pass rate?

Of the years with at least 100 tests, the 2016 Mercedes SLK has the highest MOT pass rate at 89% and the 1996 the lowest at 76%. Newer cars usually pass more often simply because they are younger and have done fewer miles.

What is the average mileage for a 2012 Mercedes SLK?

The average mileage recorded at MOT tests on the 2012 Mercedes SLK is 64,940 miles, which is below the expected 88,800 miles for a 12-year-old car. This suggests lighter use than average, which generally means less wear on major components.