73 Auto Research
Petrol vs diesel: UK car ownership costs compared
Across the 24 petrol and 16 diesel cars 73 Auto has analysed under one standard scenario, the median petrol car costs £5,303 a year to own and the median diesel £5,774. The average points the other way (£5,943 petrol, £5,698 diesel), because a few expensive cars pull one group's average up. In these examples, neither fuel is simply cheaper to own: the car itself matters more than what it runs on. These are 73 Auto estimates from its own examples, not official statistics.
Published 2026-09-28 · Publisher: 73 Auto · Download the data (CSV)
At a glance
| Figure | Value | Basis |
|---|---|---|
| Petrol: median annual cost | £5,303 | n = 24 |
| Petrol: average annual cost | £5,943 | n = 24 |
| Petrol: median monthly cost | £442 | n = 24 |
| Petrol: median cost per mile | £0.72 | n = 24 |
| Petrol: lowest to highest | £4,411 – £9,650 | n = 24 |
| Petrol: median model year | 2017 | n = 24 |
| Diesel: median annual cost | £5,774 | n = 16 |
| Diesel: average annual cost | £5,698 | n = 16 |
| Diesel: median monthly cost | £481 | n = 16 |
| Diesel: median cost per mile | £0.78 | n = 16 |
| Diesel: lowest to highest | £4,284 – £7,128 | n = 16 |
| Diesel: median model year | 2016 | n = 16 |
Scenario for every figure: 7,400 miles a year, 3-year ownership, finance purchase. Hybrid and electric cars are not part of this comparison; see the electric vs petrol and diesel study.
Why the median and the average can disagree
A median is the middle car; an average is pulled towards unusually cheap or expensive ones. The five dearest cars in this comparison are Audi RS 3 TFSI quattro 2024 (petrol, £9,650), Jaguar F-Type 2014 (petrol, £9,623), BMW M3 Competition Auto 2021 (petrol, £9,506), Porsche Boxster 2006 (petrol, £8,460) and Land Rover Range Rover Sport 2015 (diesel, £7,128). Where most of the dearest cars share a fuel, that fuel's average rises well above its median.
The groups also differ in age and type: the median petrol example is from 2017, the median diesel from 2016. Age, size, performance and price shape ownership cost more than fuel type does, so a like-for-like answer needs the same car in both fuels.
Which is cheaper for you
Diesel cars typically use less fuel per mile, so the more you drive, the more a diesel's fuel saving counts against costs that don't depend on mileage. At low mileage, the fuel saving is smaller. The only reliable answer for a particular choice is to price both cars you're considering with your own mileage; see the cost per mile calculator and how fuel cost is worked out.
Compare petrol and diesel for the car you want
Enter a UK registration with your own annual mileage to see what that specific car would cost you. 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
Every petrol example
Cheapest first; each links to its full breakdown.
| Vehicle | Fuel | Per year | Per month | Per mile |
|---|---|---|---|---|
| Volkswagen Polo 2013 | Petrol | £4,411 | £368 | £0.60 |
| Vauxhall Corsa 2015 | Petrol | £4,424 | £369 | £0.60 |
| Mercedes-Benz A-Class 2012 | Petrol | £4,561 | £380 | £0.62 |
| Nissan Qashqai 2015 | Petrol | £4,584 | £382 | £0.62 |
| Vauxhall Astra 2012 | Petrol | £4,722 | £393 | £0.64 |
| Ford EcoSport 2020 | Petrol | £4,794 | £399 | £0.65 |
| Ford Puma ST-Line X mHEV 2020 | Petrol | £4,807 | £401 | £0.65 |
| Ford Focus 2020 | Petrol | £4,811 | £401 | £0.65 |
| Hyundai Tucson 2016 | Petrol | £4,850 | £404 | £0.66 |
| Honda Civic 2009 | Petrol | £4,992 | £416 | £0.67 |
| Skoda Octavia 2017 | Petrol | £5,034 | £420 | £0.68 |
| MINI Mini 2018 | Petrol | £5,078 | £423 | £0.69 |
| Peugeot 308 Allure Premium PureTech S&S auto 2023 | Petrol | £5,527 | £461 | £0.75 |
| BMW 3 Series 2012 | Petrol | £5,787 | £482 | £0.78 |
| Volvo XC40 2019 | Petrol | £5,809 | £484 | £0.79 |
| Volkswagen Golf 2015 | Petrol | £5,878 | £490 | £0.79 |
| Honda CR-V 2017 | Petrol | £5,940 | £495 | £0.80 |
| Skoda Kodiaq 2022 | Petrol | £6,208 | £517 | £0.84 |
| Mercedes-Benz A-Class 2019 | Petrol | £6,425 | £535 | £0.87 |
| MG HS Trophy 2024 | Petrol | £6,744 | £562 | £0.91 |
| Porsche Boxster 2006 | Petrol | £8,460 | £705 | £1.14 |
| BMW M3 Competition Auto 2021 | Petrol | £9,506 | £792 | £1.28 |
| Jaguar F-Type 2014 | Petrol | £9,623 | £802 | £1.30 |
| Audi RS 3 TFSI quattro 2024 | Petrol | £9,650 | £804 | £1.30 |
Every diesel example
Cheapest first; each links to its full breakdown.
| Vehicle | Fuel | Per year | Per month | Per mile |
|---|---|---|---|---|
| Ford Fiesta 2010 | Diesel | £4,284 | £357 | £0.58 |
| Mazda 5 2012 | Diesel | £4,543 | £379 | £0.61 |
| Volkswagen Golf 2016 | Diesel | £4,552 | £379 | £0.62 |
| Nissan Juke 2015 | Diesel | £4,782 | £398 | £0.65 |
| Kia Sportage 2013 | Diesel | £5,357 | £446 | £0.72 |
| Volkswagen Tiguan 2017 | Diesel | £5,686 | £474 | £0.77 |
| Audi A3 2014 | Diesel | £5,690 | £474 | £0.77 |
| Toyota RAV4 2017 | Diesel | £5,691 | £474 | £0.77 |
| Land Rover Discovery Sport 2018 | Diesel | £5,856 | £488 | £0.79 |
| Mercedes-Benz GLC 2016 | Diesel | £5,934 | £494 | £0.80 |
| Land Rover Range Rover Evoque 2014 | Diesel | £5,989 | £499 | £0.81 |
| Jaguar E-Pace 2018 | Diesel | £6,150 | £512 | £0.83 |
| Land Rover Defender First Edition D Auto 2020 | Diesel | £6,157 | £513 | £0.83 |
| BMW X3 2019 | Diesel | £6,407 | £534 | £0.87 |
| Volkswagen Touareg 2008 | Diesel | £6,964 | £580 | £0.94 |
| Land Rover Range Rover Sport 2015 | Diesel | £7,128 | £594 | £0.96 |
Method
Every petrol and diesel vehicle in 73 Auto's indexable Real Car Cost Examples dataset is included. Each figure is that vehicle's estimated total ownership cost (depreciation, fuel, insurance, servicing, repairs, tyres, tax and finance) from a full 73 Auto report. The study compares headline totals only; it doesn't compare individual cost categories. It is published only while both groups have at least five vehicles. See the methodology and data sources.
Limitations
24 petrol and 16 diesel cars is a small sample of specific vehicles, not a representative sample of UK cars, and every figure uses one ownership scenario.
The underlying reports were calculated on 21 Jul 2026 with the cost models in use at the time. 73 Auto has since rebuilt its fuel prices and VED rules, tyres, servicing, repairs and maintenance, depreciation and insurance models, so the per-category figures describe those earlier models; a new report for the same vehicle can differ. They will be refreshed when the examples are recalculated.
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.