MERCEDES 420 (1991)
Running costs, common problems, and reliability data based on 44 real MOT tests in 2024.
MOT Pass Rate
77%
Total Tests (2024)
44
Avg Mileage
131,577 mi
Est. Annual Cost
£2,397
Is the 1991 MERCEDES 420 reliable?
Average reliability. Expect some repairs as it ages. That's close to the national average of 82%. It falls below the MERCEDES brand average of 87%.
At 33 years old, 77% of MERCEDES 420s from 1991 passed their MOT first time in 2024. That's based on 44 tests across the UK. The average mileage at this age is 131,577 miles.
How does the 1991 MERCEDES 420 compare?
Mileage Analysis
The average 1991 MERCEDES 420 has 131,577 miles on the clock, which is below the expected 244,200 miles for a 33-year-old car. This suggests lighter use than average, which generally means less wear on major components.
How much does a 1991 MERCEDES 420 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.
Checking a specific MERCEDES 420?
Enter the reg plate to see its individual MOT history, mileage verification, and predicted costs.
About the 1991 MERCEDES 420
The 1991 MERCEDES 420 is a performance with a 4196cc petrol engine. 44 of these vehicles were MOT tested in 2024, making it a rare model on UK roads. Among all cars from 1991, the average MOT pass rate is 78%, and this model falls short of that benchmark.
With an average of 131,577 miles at 33 years old, MERCEDES 420 owners tend to use this car less than the typical driver.
1991 MERCEDES 420 Fuel Costs
The 4196cc 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 1991 MERCEDES 420?
Total estimated annual running cost is £2,397 (£200/month), broken down as £1592 fuel, £250 road tax, £55 MOT, and £500 predicted repairs. Repair costs are moderate, reflecting the 77% pass rate. Keeping on top of servicing will help avoid surprises.
Buying a Used 1991 MERCEDES 420
At 33 years old, the MERCEDES 420 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. Note: with only 44 tests in our data, these figures should be treated as indicative rather than definitive.
Alternatives to the 1991 MERCEDES 420
If reliability is your priority, there are 4 similar cars with a higher MOT pass rate. Here are comparable petrol cars with similar engines:
- LAND ROVER RANGE ROVER (1993) 81% pass rate (+4%) from 1,021 tests
- JAGUAR XJS (1993) 84% pass rate (+7%) from 925 tests
- TVR GRIFFITH (1992) 88% pass rate (+11%) from 517 tests
- TVR CHIMAERA (1993) 84% pass rate (+7%) from 346 tests