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Cost guide

The cost of keeping an old car

Keeping an old car usually means paying less in depreciation, because most of its value has already gone, and more in repairs, because wear and failures become more likely with age and mileage and no manufacturer's warranty covers them. Whether keeping it is cheaper than replacing it depends on both cars: the reliable way to decide is to price your car and the one you'd replace it with on the same mileage and ownership period.

Check what a specific car really costs to own

Published 2026-09-28 · Publisher: 73 Auto

Price the car you already own

Enter your registration and how long you'd keep it, then do the same for the car you're considering. Your first check is free and shows the vehicle summary and its headline ownership cost. The category-by-category breakdown is part of a paid check.

UK number plate or 17-character VIN

What changes as a car gets older

  • Depreciation slows. Value falls fastest in a car's first years, so an older car loses fewer pounds each year. See the depreciation calculator.
  • Repairs rise. 73 Auto projects each part's chance of wearing out or failing year by year from DVSA MOT results for similar cars at the same age and mileage. See car maintenance cost.
  • The MOT matters more. Every year brings an MOT, and advisories on the latest one are costed as near-term repairs. See MOT cost.
  • Road tax follows the registration date. Older cars stay on the VED rules that applied when they were first registered. See the car tax check.
  • There is no finance to pay. If the car is paid off, there is no interest line at all, which a replacement bought on finance would add.

How to compare keeping with replacing

  1. Run your own car's registration with your real annual mileage and the years you'd keep it.
  2. Run the registration of the car you'd replace it with (any UK-registered car, new or used) with the same mileage and period, and how you'd pay for it.
  3. Compare the two totals. The replacement's total already includes the value it would lose while you own it and any finance interest, which is the cost most often left out of a keep-or-replace decision.

The comparison covers running and ownership costs, not what you'd get for your current car when you sell it or part-exchange it, so factor that in separately.

Older cars in 73 Auto's examples

The 13 worked examples that were at least 12 years old when calculated, cheapest first. Each links to its full breakdown.

Older cars in 73 Auto's examples
VehicleFuelPer yearPer monthPer mile
Ford Fiesta 2010Diesel£4,284£357£0.58
Volkswagen Polo 2013Petrol£4,411£368£0.60
Mazda 5 2012Diesel£4,543£379£0.61
Mercedes-Benz A-Class 2012Petrol£4,561£380£0.62
Vauxhall Astra 2012Petrol£4,722£393£0.64
Honda Civic 2009Petrol£4,992£416£0.67
Kia Sportage 2013Diesel£5,357£446£0.72
Audi A3 2014Diesel£5,690£474£0.77
BMW 3 Series 2012Petrol£5,787£482£0.78
Land Rover Range Rover Evoque 2014Diesel£5,989£499£0.81
Volkswagen Touareg 2008Diesel£6,964£580£0.94
Porsche Boxster 2006Petrol£8,460£705£1.14
Jaguar F-Type 2014Petrol£9,623£802£1.30

About these examples. All 53 were calculated under one standard scenario: 7,400 miles a year, 3-year ownership, finance purchase. They describe the specific vehicles 73 Auto has analysed, not every car of that type in the UK. They were calculated on 21 Jul 2026. Since then, 73 Auto has rebuilt its fuel prices and VED rules, tyres, servicing, repairs and maintenance, depreciation and insurance models, so a new report for the same car today can give different figures from its example.

Common questions

Is it always cheaper to keep an old car?

Often, but not always. A reliable old car with little left to lose can be very cheap to keep; one facing expensive repairs, high fuel use or high road tax can cost more than a newer replacement. Price both on the same assumptions to find out.

Does the estimate know about my car’s condition?

It knows what the car's official records show, including its MOT history, but not its service record or anything a mechanic would spot. See the used car cost calculator for how the MOT history is used.

Limitations

Repair costs for older cars are the most uncertain part of any estimate, because condition and past maintenance vary so much. Treat the figure as a budget for comparing options, not a prediction.

How 73 Auto works this out

Every category is explained in the methodology, and the data sources page lists which inputs are official data and which are 73 Auto estimates. How pages are written and kept up to date is set out in the editorial policy; to report a factual error, see corrections.

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