Is the 2020 BMW 420 reliable?

Excellent reliability. Very few MOT failures. 92% of BMW 420s from 2020 passed their MOT first time in 2026, based on 6,832 tests. That's 10 points above the national average of 82%.

How much does a 2020 BMW 420 cost to run?

Estimated annual running cost is £1,487 (£124/month), including £1037 fuel, £195 road tax, £55 MOT, and £200 predicted repairs.

What is the MOT pass rate for a 2020 BMW 420?

The 2020 BMW 420 has a 92% MOT pass rate based on 6,832 tests in 2026. This ranks 1243 out of 2596 cars from 2020.

Which year BMW 420 is most reliable?

The 2021 BMW 420 has the highest MOT pass rate at 94%. The least reliable year is 2013 at 85%.

BMW 420 (2020)

Q: What is the average mileage for a 2020 BMW 420?

The average mileage for a 2020 BMW 420 is 32,973 miles, 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.

Running costs, reliability data, and common problems from 6,832 real MOT tests.

Annual Cost

£1,487

£124/month

MOT Pass Rate

92%

Excellent

Road Tax

£195

Flat rate/year

Insurance

Grp 18-32

1995cc Diesel

Great Choice

92% pass rate, £1487/year to run. 10 points above average.

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Diesel1995cc6 years old6,832 tests33k miles avg

Annual Running Costs

Fuel (Diesel, 1995cc)

~48 mpg

£1,037

Road Tax

Flat rate (post-2017)

£195

MOT Test

£55

Predicted Repairs

Low estimate due to excellent reliability

£200

Total per year£1,487

Per month£124/mo

Per week£29/wk

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

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Reliability Verdict

92% MOT pass rate(Excellent)

0%National avg: 82%100%

Excellent reliability. Very few MOT failures. That's 10 points above the national average of 82%. It also outperforms the BMW brand average of 88%.

At 6 years old, 92% of BMW 420s from 2020 passed their MOT first time in 2026. That's based on 6,832 tests across the UK. The average mileage at this age is 32,973 miles.

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How Does It Compare?

Rank among 2020 cars1243th of 2,596(top 48%)

Rank among BMW models445th of 1,564(top 28%)

vs national average+10%(82% avg)

vs 2020 cars average+0%(92% avg)

vs BMW average+4%(88% avg)

Mileage Analysis

32,973

Average miles

44,400

Expected for age

The average 2020 BMW 420 has 32,973 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.

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Best Year to Buy?

The most reliable year is the 2021 model with a 94% MOT pass rate, while the 2013 model has the lowest at 85%. The 2020 sits between the two at 92%.

BMW 420 by Year

Year	Pass Rate	Tests	Avg Mileage
2021	94%	730	28,172 mi
2020	92%	6,832	32,973 mi
2019	90%	16,835	41,885 mi
2018	91%	22,374	51,167 mi
2017	90%	25,467	64,302 mi
2016	89%	25,224	75,338 mi
2015	88%	23,559	82,955 mi
2014	86%	18,990	89,334 mi
2013	85%	1,309	99,720 mi

Similar Cars to Consider

VOLKSWAGEN GOLF

2018 · 1968cc Diesel

£1,482/year

92%

same

FORD FOCUS

2019 · 1499cc Diesel

£1,500/year

89%

-3%

VOLKSWAGEN POLO

2018 · 1598cc Diesel

£1,500/year

84%

-8%

FORD KUGA

2019 · 1997cc Diesel

£1,482/year

91%

-1%

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About the 2020 BMW 420

The 2020 BMW 420 is a premium with a 1995cc diesel engine. 6,832 of these vehicles were MOT tested in 2026, making it a reasonably common sight on UK roads. Among all cars from 2020, the average MOT pass rate is 92%, and this model falls short of that benchmark.

With an average of 32,973 miles at 6 years old, BMW 420 owners tend to use this car less than the typical driver.

2020 BMW 420 Fuel Costs

The 1995cc diesel engine offers a reasonable balance between performance and economy. Expect around 48 mpg in mixed driving, which works out to roughly £1,037 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 2020 BMW 420?

Total estimated annual running cost is £1,487 (£124/month), broken down as £1037 fuel, £195 road tax, £55 MOT, and £200 predicted repairs. The low repair estimate reflects the excellent 92% pass rate. These cars rarely fail their MOT, so unexpected bills are less likely.

BMW 420 Reliability Trend

Newer BMW 420s show better MOT pass rates than older ones, with an average improvement of 4 percentage points.

Buying a Used 2020 BMW 420

At 6 years old, the BMW 420 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 2021 model has the highest pass rate at 94%. With 6,832 MOT tests in our data, there's strong statistical confidence in these figures.

Common Issues to Watch For

Based on the 2020 BMW 420's fuel type, age, and engine size, these are the most likely problem areas to check.

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

Medium risk

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

AdBlue System

Medium risk

Post-2015 diesels use AdBlue for emissions. Sensor failures and tank heater issues are common. Budget £200-£500 for repairs.

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.

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 2020 BMW 420 stacks up against similar cars for annual running costs, insurance, and tax.

Car	Pass Rate	Fuel/yr	Tax/yr	Insurance	Total/yr
BMW 420(2020)	92%	£1037	£195	Grp 18-32	£1487
VOLKSWAGEN GOLF(2018)	92%	£1037	£190	Grp 18-32	£1482-£5
FORD FOCUS(2019)	89%	£905	£190	Grp 12-25	£1500+£13
VOLKSWAGEN POLO(2018)	84%	£905	£190	Grp 12-25	£1500+£13
FORD KUGA(2019)	91%	£1037	£190	Grp 18-32	£1482-£5

Estimates based on 7,400 miles/year, current fuel prices, and MOT data. Insurance groups are indicative. Actual costs vary by driver, location, and usage.