MERCEDES GLS (2018)
Running costs, common problems, and reliability data based on 1,328 real MOT tests in 2024.
MOT Pass Rate
90%
Total Tests (2024)
1,328
Avg Mileage
55,325 mi
Est. Annual Cost
£1,690
Is the 2018 MERCEDES GLS reliable?
Excellent reliability. Very few MOT failures. That's 8 points above the national average of 82%.
At 6 years old, 90% of MERCEDES GLSs from 2018 passed their MOT first time in 2024. That's based on 1,328 tests across the UK. The average mileage at this age is 55,325 miles.
How does the 2018 MERCEDES GLS compare?
Mileage Analysis
The average 2018 MERCEDES GLS has 55,325 miles on the clock, which is above the expected 44,400 miles for a 6-year-old car. Higher-mileage cars often have more motorway miles, which is generally less harmful than stop-start urban driving.
Best year to buy a MERCEDES GLS?
The most reliable year is the 2016 model with a 93% MOT pass rate, while the 2018 model has the lowest at 90%. Consider a different year if reliability is a priority.
How much does a 2018 MERCEDES GLS cost to run?
Based on 7,400 miles/year (UK average), current fuel prices, and repair likelihood from MOT pass rate data. Insurance not included.
MERCEDES GLS by Year
Checking a specific MERCEDES GLS?
Enter the reg plate to see its individual MOT history, mileage verification, and predicted costs.
About the 2018 MERCEDES GLS
The 2018 MERCEDES GLS is a large car with a 2987cc diesel engine. 1,328 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 55,325 miles at 6 years old, MERCEDES GLS owners cover more miles than the average driver.
2018 MERCEDES GLS Fuel Costs
The 2987cc 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 £1,245 per year at current diesel prices of 148p per litre (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 2018 MERCEDES GLS?
Total estimated annual running cost is £1,690 (£141/month), broken down as £1245 fuel, £190 road tax, £55 MOT, and £200 predicted repairs. The low repair estimate reflects the excellent 90% pass rate. These cars rarely fail their MOT, so unexpected bills are less likely.
MERCEDES GLS Reliability Trend
The MERCEDES GLS has maintained consistent MOT pass rates across model years, varying by only 2 percentage points.
Buying a Used 2018 MERCEDES GLS
At 6 years old, the MERCEDES GLS offers good value with plenty of life remaining. Most manufacturer warranties will have expired, so a pre-purchase inspection is worth the cost.
Alternatives to the 2018 MERCEDES GLS
If reliability is your priority, there's one similar car with a higher MOT pass rate. Here are comparable diesel cars with similar engines:
- MERCEDES E (2019) 90% pass rate (same) from 41,000 tests
- MERCEDES GLC (2018) 91% pass rate (+1%) from 40,494 tests
- AUDI A5 (2017) 89% pass rate (-1%) from 33,531 tests
- FORD RANGER (2019) 87% pass rate (-3%) from 32,194 tests