CarCostCheck

MERCEDES SL (2018)

Running costs, common problems, and reliability data based on 1,022 real MOT tests in 2024.

MOT Pass Rate

93%

Total Tests (2024)

1,022

Avg Mileage

25,750 mi

Est. Annual Cost

£2,037

Is the 2018 MERCEDES SL reliable?

Excellent reliability. Very few MOT failures. That's 11 points above the national average of 82%. It also outperforms the MERCEDES brand average of 87%.

At 6 years old, 93% of MERCEDES SLs from 2018 passed their MOT first time in 2024. That's based on 1,022 tests across the UK. The average mileage at this age is 25,750 miles.

How does the 2018 MERCEDES SL compare?

Rank among all 2018 cars187th out of 649(top 29%)
Rank among all MERCEDES models383th out of 1,408(top 27%)
vs national average+11% (82% avg)
vs 2018 cars average+4% (89% avg)
vs MERCEDES average+6% (87% avg)

Mileage Analysis

The average 2018 MERCEDES SL has 25,750 miles on the clock, which is below the expected 44,400 miles for a 6-year-old car. This suggests lighter use than average, which generally means less wear on major components.

Best year to buy a MERCEDES SL?

The most reliable year is the 2019 model with a 97% MOT pass rate, while the 1990 model has the lowest at 81%. The 2018 sits between the two at 93%.

How much does a 2018 MERCEDES SL cost to run?

Fuel (Petrol, 4663cc)
£1,592
🏛️Road Tax
£190
🔧MOT Test
£55
🛠️Predicted Repairs
£200
Total per year£2,037
Per month£170/mo

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

MERCEDES SL by Year

YearPass RateTestsAvg Mileage
201997%85119,987 mi
201893%1,02225,750 mi
201794%1,84730,630 mi
201695%2,24036,109 mi
201592%2,22240,591 mi
201492%2,89247,357 mi
201389%2,79649,450 mi
201290%1,13650,476 mi
201192%57950,602 mi
201088%95562,402 mi
200987%1,22263,020 mi
200890%1,94065,610 mi
200788%1,79271,215 mi
200687%1,83273,640 mi
200588%2,43075,394 mi
200488%4,03677,676 mi
200386%5,17375,808 mi
200288%2,08374,421 mi
200190%52878,534 mi
200086%95584,195 mi
199987%1,61784,924 mi
199886%2,01889,595 mi
199787%2,11793,418 mi
199688%1,77893,971 mi
199585%1,62799,248 mi
199488%1,24493,271 mi
199388%46285,167 mi
199287%31290,571 mi
199186%28878,703 mi
199081%18688,429 mi

Checking a specific MERCEDES SL?

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About the 2018 MERCEDES SL

The 2018 MERCEDES SL is a performance with a 4663cc petrol engine. 1,022 of these vehicles were MOT tested in 2024, making it a reasonably common sight on UK roads. Among all cars from 2018, the average MOT pass rate is 89%, and this model beats that benchmark.

With an average of 25,750 miles at 6 years old, MERCEDES SL owners tend to use this car less than the typical driver.

2018 MERCEDES SL Fuel Costs

The 4663cc 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 2018 MERCEDES SL?

Total estimated annual running cost is £2,037 170/month), broken down as £1592 fuel, £190 road tax, £55 MOT, and £200 predicted repairs. The low repair estimate reflects the excellent 93% pass rate. These cars rarely fail their MOT, so unexpected bills are less likely.

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 2018 MERCEDES SL

At 6 years old, the MERCEDES SL offers good value with plenty of life remaining. Most manufacturer warranties will have expired, so a pre-purchase inspection is worth the cost. If you're flexible on year, the 2019 model has the highest pass rate at 97%.

Alternatives to the 2018 MERCEDES SL

If reliability is your priority, there are 2 similar cars with a higher MOT pass rate. Here are comparable petrol cars with similar engines: