The purchase price of a car is only the beginning. True ownership cost includes fuel, insurance, tax, MOT, servicing, tyres, and depreciation — the largest cost of all for most owners.
Depreciation: The Hidden Biggest Cost
A new car typically loses 15-25% of value in year one and 50-60% over three years — purely from value loss, before driving a single mile.
£25,000 new car → £4,000-£5,000/year lost to depreciation alone (first 3 years)
Buying a 2-3 year old car that has already absorbed the steepest depreciation curve is significantly more economical than buying new.
Fuel
Annual fuel cost = (Annual mileage ÷ MPG) × Fuel price per gallon
Official fuel economy figures rarely reflect real-world driving — most drivers achieve 10-20% less than the official figure, particularly in urban driving, motorway speeds above 70mph, and cold weather.
Insurance, Tax, and Servicing
| Cost Category | Key Factor |
|---|---|
| Insurance | Compare annually — auto-renewal is rarely the best price |
| Road tax (UK) | Based on CO2 emissions; electric vehicles currently exempt |
| MOT | Required annually after 3 years; max £54.85 test cost |
| Servicing | Following manufacturer schedule prevents costly failures |
Tyres
Budget tyres (4 fitted): £150-£200. Premium tyres: £400-£600. Premium tyres typically offer shorter braking distances and better wet grip — a meaningful safety factor, not just a cost consideration.
Reducing Running Costs
Choosing a car with a strong reliability record reduces the likelihood of unexpected repair bills appearing without warning. Reliability data from owner surveys is widely published and shows considerable variation between manufacturers and even specific models, so it's worth checking before committing to a purchase rather than relying on brand reputation alone. Maintaining the car according to its specified service schedule, rather than stretching intervals to save money in the short term, prevents many of the more expensive failures that tend to follow neglected maintenance.
Comparing insurance annually rather than accepting automatic renewal consistently reduces premiums over time, since insurers frequently offer better rates to new customers than to those simply renewing. For high-mileage drivers, fuel efficiency becomes the dominant running cost and may justify paying a premium for a more economical vehicle upfront. For low-mileage drivers, depreciation and fixed costs dominate instead, which generally makes a lower purchase price more valuable than chasing small fuel economy differences between similar models.
Choose a model with a strong reliability record to reduce unexpected repairs. Compare insurance annually rather than accepting auto-renewal. For high-mileage drivers, fuel efficiency dominates running costs; for low-mileage drivers, depreciation and fixed costs matter more than fuel economy.
Electric Vehicle Running Cost Differences
Electric vehicles shift the balance of running costs considerably compared to petrol or diesel equivalents. Fuel costs are typically much lower per mile when charging at home on a standard or off-peak electricity tariff, though costs rise significantly when relying on public rapid charging networks, which often charge a meaningful premium over home charging rates. Servicing costs also tend to be lower for electric vehicles, since they have far fewer moving parts than an internal combustion engine and no oil changes, exhaust systems, or clutch components to maintain.
Depreciation patterns for electric vehicles have historically been less predictable than for petrol and diesel cars, partly due to rapidly evolving battery technology and rapidly changing public charging infrastructure affecting buyer confidence. Battery degradation over time is a genuine consideration, though most manufacturers now offer battery warranties of 8 years or 100,000 miles guaranteeing a minimum retained capacity, which provides meaningful reassurance for anyone concerned about long-term running costs and resale value.