Is the 2021 MG 3 reliable?

Excellent reliability. Very few MOT failures. 92% of MG 3s from 2021 passed their MOT first time in 2026, based on 1,100 tests. That's 10 points above the national average of 82%.

How much does a 2021 MG 3 cost to run?

Estimated annual running cost is £1,587 (£132/month), including £1137 fuel, £195 road tax, £55 MOT, and £200 predicted repairs.

What is the MOT pass rate for a 2021 MG 3?

The 2021 MG 3 has a 92% MOT pass rate based on 1,100 tests in 2026. This ranks 1898 out of 3373 cars from 2021.

Which year MG 3 is most reliable?

The 2021 MG 3 has the highest MOT pass rate at 92%. The least reliable year is 2014 at 79%.

MG 3 (2021)

Q: What is the average mileage for a 2021 MG 3?

The average mileage for a 2021 MG 3 is 19,633 miles, which is below the expected 37,000 miles for a 5-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 1,100 real MOT tests.

Annual Cost

£1,587

£132/month

MOT Pass Rate

92%

Excellent

Road Tax

£195

Flat rate/year

Insurance

Grp 12-25

1498cc Petrol

Great Choice

92% pass rate, £1587/year to run. 10 points above average.

Buying this car? Check for finance, write-offs & theft

£4.99

Check a specific MG 3

Enter a reg plate for full MOT history, mileage check, health score, running costs, and reliability data. Free, instant, no signup.

Petrol1498cc5 years old1,100 tests20k miles avg

Annual Running Costs

Fuel (Petrol, 1498cc)

~42 mpg

£1,137

Road Tax

Flat rate (post-2017)

£195

MOT Test

£55

Predicted Repairs

Low estimate due to excellent reliability

£200

Total per year£1,587

Per month£132/mo

Per week£31/wk

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

🛡️

Get an insurance quote for this MG 3

Compare quotes and find the best deal

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 MG brand average of 86%.

At 5 years old, 92% of MG 3s from 2021 passed their MOT first time in 2026. That's based on 1,100 tests across the UK. The average mileage at this age is 19,633 miles.

Got a MG 3 you're looking at?

Enter the reg plate to check its specific MOT history, mileage, and health score.

How Does It Compare?

Rank among 2021 cars1898th of 3,373(top 56%)

Rank among MG models49th of 155(top 32%)

vs national average+10%(82% avg)

vs 2021 cars average+0%(92% avg)

vs MG average+6%(86% avg)

Mileage Analysis

19,633

Average miles

37,000

Expected for age

The average 2021 MG 3 has 19,633 miles on the clock, which is below the expected 37,000 miles for a 5-year-old car. This suggests lighter use than average, which generally means less wear on major components.

Looking at a specific MG 3?

Enter its reg plate for a free check with full MOT history, mileage verification, and predicted costs.

MG 3 by Year

Year	Pass Rate	Tests	Avg Mileage
2022	91%	141	19,942 mi
2021	92%	1,100	19,633 mi
2020	90%	2,869	24,046 mi
2019	88%	6,117	29,253 mi
2018	85%	4,329	36,732 mi
2017	80%	5,135	43,780 mi
2016	82%	5,218	48,631 mi
2015	79%	4,075	53,548 mi
2014	79%	2,698	57,573 mi
2013	86%	200	60,551 mi

Similar Cars to Consider

FORD FIESTA

2019 · 998cc Petrol

£1,400/year

91%

-1%

VOLKSWAGEN GOLF

2019 · 1498cc Petrol

£1,582/year

92%

same

VAUXHALL CORSA

2019 · 1398cc Petrol

£1,732/year

88%

-4%

NISSAN QASHQAI

2020 · 1598cc Petrol

£1,582/year

93%

+1%

Check a Specific Mg 3

Enter a reg plate to get the full MOT history, health score, and mileage verification.

Upgrade to Premium (£4.99) for stolen, finance, and write-off checks.

About the 2021 MG 3

The 2021 MG 3 is a small family car with a 1498cc petrol engine. 1,100 of these vehicles were MOT tested in 2026, making it a reasonably common sight on UK roads. Among all cars from 2021, the average MOT pass rate is 92%, and this model falls short of that benchmark.

With an average of 19,633 miles at 5 years old, MG 3 owners tend to use this car less than the typical driver.

2021 MG 3 Fuel Costs

The 1498cc 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 MG 3?

Total estimated annual running cost is £1,587 (£132/month), broken down as £1137 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.

MG 3 Reliability Trend

Newer MG 3s show better MOT pass rates than older ones, with an average improvement of 8 percentage points.

Buying a Used 2021 MG 3

At 5 years old, the MG 3 offers good value with plenty of life remaining. Most manufacturer warranties will have expired, so a pre-purchase inspection is worth the cost.

Common Issues to Watch For

Based on the 2021 MG 3's fuel type, age, and engine size, these are the most likely problem areas to check.

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 2021 MG 3 stacks up against similar cars for annual running costs, insurance, and tax.

Car	Pass Rate	Fuel/yr	Tax/yr	Insurance	Total/yr
MG 3(2021)	92%	£1137	£195	Grp 12-25	£1587
FORD FIESTA(2019)	91%	£955	£190	Grp 1-8	£1400-£187
VOLKSWAGEN GOLF(2019)	92%	£1137	£190	Grp 12-25	£1582-£5
VAUXHALL CORSA(2019)	88%	£1137	£190	Grp 8-20	£1732+£145
NISSAN QASHQAI(2020)	93%	£1137	£190	Grp 12-25	£1582-£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.