CarCostCheck

MERCEDES GL (2021)

Running costs, common problems, and reliability data based on 71 real MOT tests in 2024.

MOT Pass Rate

99%

Total Tests (2024)

71

Avg Mileage

29,185 mi

Est. Annual Cost

£1,582

Is the 2021 MERCEDES GL reliable?

Excellent reliability. Very few MOT failures. That's 17 points above the national average of 82%. It also outperforms the MERCEDES brand average of 87%.

At 3 years old, 99% of MERCEDES GLs from 2021 passed their MOT first time in 2024. That's based on 71 tests across the UK. The average mileage at this age is 29,185 miles.

How does the 2021 MERCEDES GL compare?

Rank among all 2021 cars155th out of 3,373(top 5%)
Rank among all MERCEDES models70th out of 1,408(top 5%)
vs national average+17% (82% avg)
vs 2021 cars average+7% (92% avg)
vs MERCEDES average+12% (87% avg)

Mileage Analysis

The average 2021 MERCEDES GL has 29,185 miles on the clock, which is above the expected 22,200 miles for a 3-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 GL?

The most reliable year is the 2020 model with a 100% MOT pass rate, while the 2006 model has the lowest at 78%. The 2021 sits between the two at 99%.

How much does a 2021 MERCEDES GL cost to run?

Fuel (Petrol, 1300cc)
£1,137
🏛️Road Tax
£190
🔧MOT Test
£55
🛠️Predicted Repairs
£200
Total per year£1,582
Per month£132/mo

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

MERCEDES GL by Year

YearPass RateTestsAvg Mileage
202199%7129,185 mi
2020100%6941,984 mi
201993%13735,018 mi
201895%6338,524 mi
201779%47108,751 mi
201688%47573,156 mi
201589%1,28379,394 mi
201492%1,32193,766 mi
201390%1,304103,757 mi
201289%22599,410 mi
201186%609116,582 mi
201089%435121,550 mi
200981%224126,000 mi
200884%371122,229 mi
200785%572130,779 mi
200678%160123,042 mi

Checking a specific MERCEDES GL?

Enter the reg plate to see its individual MOT history, mileage verification, and predicted costs.

GB

Free instant check using official DVSA and DVLA data

About the 2021 MERCEDES GL

The 2021 MERCEDES GL is a small family car with a 1300cc petrol engine. 71 of these vehicles were MOT tested in 2024, making it a rare model on UK roads. It ranks in the top 5% of all 2021 cars for reliability.

With an average of 29,185 miles at 3 years old, MERCEDES GL owners cover more miles than the average driver.

2021 MERCEDES GL Fuel Costs

The 1300cc petrol engine offers a reasonable balance between performance and economy. Expect around 42 mpg in mixed driving, which works out to roughly £1,137 per year at current petrol prices of 142p per litre (based on 7,400 miles per year).

What does it cost to own a 2021 MERCEDES GL?

Total estimated annual running cost is £1,582 132/month), broken down as £1137 fuel, £190 road tax, £55 MOT, and £200 predicted repairs. The low repair estimate reflects the excellent 99% pass rate. These cars rarely fail their MOT, so unexpected bills are less likely.

MERCEDES GL Reliability Trend

Newer MERCEDES GLs show better MOT pass rates than older ones, with an average improvement of 9 percentage points.

Buying a Used 2021 MERCEDES GL

At 3 years old, this is still relatively fresh. You may find examples with remaining manufacturer warranty. Depreciation is slowing but hasn't bottomed out yet. If you're flexible on year, the 2020 model has the highest pass rate at 100%. Note: with only 71 tests in our data, these figures should be treated as indicative rather than definitive.

Alternatives to the 2021 MERCEDES GL

The MERCEDES GL is actually the most reliable option among similar petrol small family cars from this era. Here are comparable petrol cars with similar engines: