Guides

What our data says about choosing, running and keeping a car, in plain English. Every figure comes from DVSA MOT results or an official source, and updates when the data does.

• The most and least reliable car brands in the UK

  Every major brand ranked on MOT results, allowing for the age and mileage of its cars, and why premium brands come out on top.

  Updated 29 October 2026

• The most reliable car of each type: superminis to SUVs

  The three models with the best MOT record in each class, for anyone who knows the kind of car they want but not which one.

  Updated 29 October 2026

• Known weak spots: the cars that fail most on brakes, steering and suspension

  For each part of the car, the popular models that fail on it far more often than average, so you know what to check before you buy.

  Updated 29 October 2026

• HMRC mileage allowance explained: 55p a mile and what you can claim

  The tax-free mileage rates for 2026/27 and 2027/28, how to claim tax relief if your employer pays less, and worked examples.

  Updated 29 October 2026

• ULEZ and clean air zones: which cars have to pay, and where

  Every UK clean air and low emission zone, what it costs a private car, and the simple rule for whether yours is affected.

  Updated 29 October 2026

• What fails an MOT? The 10 most common faults, from 30 million tests

  The faults that fail the most cars, how many of them you can spot yourself in ten minutes, and what to check before your test.

  Updated 28 October 2026

• MOT failure rates by age: when cars start to go wrong

  How the chance of failing an MOT rises from a car's third birthday to its twentieth, and what that means when you buy used.

  Updated 28 October 2026

• Electric, hybrid, petrol or diesel: which is most reliable?

  MOT results for cars of the same age by fuel type, and the faults each kind of car fails on most. Electric cars wear tyres, not brakes.

  Updated 28 October 2026

• Company car tax 2026 to 2031: electric, hybrid and petrol compared

  Every company car tax rate now set up to 2030/31, including the rates announced in Budget 2026, with what a £40,000 car costs you each year.

  Updated 28 October 2026

• How much does it cost to run a car in 2026?

  Fuel, electricity and car tax for petrol, diesel, hybrid and electric cars at today's prices, and what changed in Budget 2026.

  Updated 28 October 2026