Vehicle Running Cost & True Cost of Ownership

Vehicle Running Cost Guide

What do I need to know about The True Cost Breakdown?

Most people dramatically underestimate vehicle running costs because they only think about fuel. Complete annual costs: fuel: approximately 20-35% of total. Insurance: 15-25%. Depreciation: 25-40% (largest cost). Servicing and tyres: 10-15%. Road tax (VED): £0-600 depending on CO2 and age. MOT: £54.85 maximum. Parking and tolls: highly variable. Finance interest (if financed): often overlooked. For a 3-year-old Ford Focus petrol, 10,000 miles/year: fuel at 40mpg, 148p/L: approximately £1,680. Insurance, servicing, MOT, road tax, and depreciation together typically add up to considerably more than fuel costs alone over a year of ownership.

What should I know about Fuel Cost Calculation?

Petrol/diesel: cost = (miles / MPG) × (fuel price per litre / 4.546). 4.546 litres per UK gallon. EV: cost = miles × (pence per kWh / 100) / miles per kWh. At 24p/kWh and 3.5 miles/kWh: 10,000 miles = 2,857 kWh × 24p = £685/year. Vs petrol at 40mpg, 148p/L: £1,680/year. EV fuel saving: approximately £995/year. Home charging vs public: home charging (7kW overnight) typically 7-15p/kWh (Economy 7 / smart tariff). Public rapid charging: 50-80p/kWh. EV running costs depend heavily on charging habits — a driver who charges almost entirely at home overnight will pay dramatically less per mile than one who relies mainly on public rapid charging.

What's the key thing to understand about Depreciation by Age and Type?

Depreciation is the biggest cost for most car owners and is largely invisible. Year 1: new car loses 15-25% of value. Year 3: typically 50-60% of new price remaining. Year 5: 35-45% of new price remaining. After year 5: depreciation slows dramatically (stable value period). Best value scenarios: buy at 2-4 years old: someone else has paid the steepest depreciation, but major mechanical issues unlikely. Fleet and lease returns in this age bracket are often well-maintained with a full dealer service history, making them a reasonable choice for buyers wanting a lower-depreciation used car.

What's the difference between EV and Petrol True Cost Comparison?

EV advantages: much lower fuel costs (assuming home charging). Lower servicing (no oil changes, fewer brake jobs due to regenerative braking). No road tax (currently zero VED for EVs). Government grants for charger installation. EV disadvantages: higher purchase price (£3,000-10,000 premium over equivalent petrol). Rapid depreciation (2022-24 data shows EVs depreciating faster than petrol). Limited range anxiety for some users. Higher insurance premiums for many models. Public charging costs can erode much of an EV's running-cost advantage if home charging isn't available, so access to a driveway or dedicated charger matters significantly to the overall comparison.

Why Depreciation Is Usually the Single Biggest Running Cost — and the Easiest to Ignore

Fuel, insurance, and maintenance are visible, recurring costs that owners track closely, but depreciation — the loss in the vehicle's resale value over time — is typically the largest single cost of car ownership and the one most easily overlooked because no bill ever arrives for it. A new car can lose a substantial portion of its value in the first few years alone, meaning two otherwise identical ownership experiences can have very different true costs depending purely on how steeply the specific model depreciates. Because depreciation is a "silent" cost realized only when you sell or trade in, calculating true cost-per-mile requires estimating it explicitly rather than just adding up fuel receipts and service invoices, which only tell part of the story.

Electric vs. Petrol/Diesel: Where the Cost Differences Actually Show Up

Electric vehicles typically cost meaningfully less per mile to "fuel," since electricity is generally cheaper per mile than petrol or diesel, especially when charged at home on a cheaper off-peak tariff, and they have fewer wearing mechanical parts (no oil changes, simpler drivetrains), which tends to reduce routine servicing costs over time. Offsetting this, EVs often carry a higher upfront purchase price, and battery degradation over many years and charge cycles is a cost dimension petrol and diesel vehicles don't have, though modern battery warranties mitigate much of that risk for the ownership period they cover. Insurance costs for EVs have historically run higher in some markets due to specialized repair costs and parts availability, though this gap has been narrowing as EVs become more common and repair networks mature.

Insurance Groups and How They Affect Your Total Running Cost

Every car sold in the UK is assigned to an insurance group, typically numbered from the lowest to the highest, that reflects factors including the car's price, repair cost, parts availability, performance, and security features, and this grouping has a direct and often underestimated effect on total running cost. Two cars with a similar purchase price and similar fuel economy can carry noticeably different insurance premiums if one sits in a significantly higher insurance group, driven by factors like engine power, how expensive and time-consuming the car is to repair, or how attractive it is to thieves, rather than by its outright price alone. For newer or younger drivers in particular, the gap in premiums between a low-group and high-group car of similar size and price can be large enough to materially change which car is actually cheaper to run overall, even if the higher-group car was cheaper to buy or more fuel-efficient. Checking a specific model's insurance group before purchase, rather than assuming insurance cost will track roughly with purchase price or engine size alone, is one of the more reliable ways to avoid an unpleasant surprise once a true running cost comparison between two shortlisted cars is actually calculated.

Reference: Approximate Annual Running Cost by Car Class

These are broad planning ranges, not quotes — insurance in particular varies enormously by driver age, location, and claims history, and depreciation depends heavily on the specific model's reputation for reliability and resale demand, which can shift year to year.

Worked Example: 3-Year Total Cost of Ownership

A family hatchback is bought for £22,000 and expected to be worth £13,500 after three years — a depreciation cost of £8,500 over the period, or roughly £2,830 a year, which is usually the single largest line item and the one drivers most often underestimate because it is never billed directly. Adding three years of fuel at an estimated £1,450/year (£4,350), insurance and tax at £950/year (£2,850), and servicing/tyres/maintenance at £500/year (£1,500): Total 3-year cost = £8,500 (depreciation) + £4,350 (fuel) + £2,850 (insurance/tax) + £1,500 (servicing) = £17,200 Average annual cost = approximately £5,730 Cost per mile at 12,000 miles/year = £5,730 / 12,000 = roughly 48p per mile Breaking the total down this way usually surprises drivers who budget only for fuel and insurance (£2,400/year combined in this example) while depreciation alone — a cost that is "paid" automatically every time the car loses value, whether driven or not — is more than double that figure.

Servicing and MOT: The Costs That Creep Up With Age

A new or nearly-new car often needs little beyond routine servicing and an annual MOT (required once a car turns three years old in the UK), but maintenance costs tend to climb steadily from around year five or six onwards as wear items like brakes, suspension components, and exhaust parts start failing more frequently. A car in its first few years might cost £150-£300 a year in servicing, while the same model at 8-10 years old, particularly if it's covered high mileage, can easily cost £500-£1,000 or more in a bad year if several components fail close together. This rising maintenance curve is one reason why buying an older car cheaply can still work out expensive overall, and why a run of repair bills is sometimes the signal that it's more economical to change the car than keep fixing it.

How Mileage Changes Which Cost Category Dominates

For a low-mileage driver covering perhaps 5,000 miles a year, fixed costs like insurance, road tax, and depreciation from simple age tend to dominate the total running cost, since fuel and wear-related maintenance stay comparatively small. For a high-mileage driver covering 20,000-30,000 miles a year, fuel cost and mileage-related depreciation become much larger factors, and servicing intervals arrive far more often in calendar terms even if the car is relatively new. This is part of why an electric vehicle's lower running cost per mile tends to look most attractive to higher-mileage drivers, while someone driving very little may never recoup a higher purchase price through fuel savings alone, making the breakeven mileage a genuinely useful number to check before assuming a given vehicle is the cheaper overall choice.