EV vs Petrol/Diesel — Total Cost of Ownership
Side-by-side comparison of electric, petrol and diesel vehicles over 3–5 years. Includes running costs, depreciation, CO₂ saved, break-even year and company car BIK tax 2025/26.
Shared assumptions
Electric Vehicle
For company car BIK — leave blank if same as purchase price
Home tariff ~28p; public rapid ~75p
Typical 3–4 miles/kWh
One-off cost — gov grant up to £350
Petrol
For BIK rate — find on V5C or manufacturer spec
Diesel
EV company car BIK rates 2024/25–2029/30
| Tax year | EV BIK % | Typical petrol 120g/km | Typical diesel 130g/km |
|---|---|---|---|
| 2024/25 | 2% | 25% | 29% |
| 2025/26 | 3% | 25% | 29% |
| 2026/27 | 4% | 26% | 30% |
| 2027/28 | 5% | 27% | 31% |
| 2028/29 | 6% | 28% | 32% |
| 2029/30 | 7% | 29% | 33% |
EV total cost of ownership tips
- Home charging is the key cost driver: Public rapid charging at 75–85p/kWh almost eliminates the fuel cost advantage over petrol. If you cannot charge at home, factor this into your cost model before switching.
- High mileage drivers benefit most:At 15,000+ miles/year, an EV's energy cost saving over petrol can exceed £1,500/year, significantly accelerating the payback on the higher purchase price.
- Company car EVs remain significantly cheaper for higher-rate taxpayers: At 3% BIK vs 25–37% for petrol, even at a £40k list price the annual BIK tax for an EV is only £480 for a basic-rate taxpayer vs £3,200–£5,920 for an equivalent petrol car.
- Salary sacrifice amplifies the EV saving: Sacrificing salary for an EV also saves employee NIC and employer NIC on the sacrificed amount — many employers pass the employer NIC saving back to employees.
- ZEV mandate affects new car availability: From 2030, all new cars sold in the UK must be zero-emission. Manufacturers are prioritising EV production — petrol/diesel model ranges will shrink from 2026 onwards, affecting availability and residual values.