BMW 320d → BYD Seal U DM-i: how much would you save?
If you're trading in your BMW 320d for a BYD Seal U DM-i, the brochure won't tell you what you actually want to know — does the maths work, and how much faster do you get back what the PHEV cost? Here's the honest answer at UK 2026 prices, 10,000 miles a year, 60% of miles on battery.
| Annual cost | BMW 320d | BYD Seal U DM-i |
|---|---|---|
| £/mile | 15.3p | 7.7p |
| 10,000 miles a year | £1,527 | £770 |
| Fuel type | diesel | petrol + grid |
Annual saving
£757
50% cheaper to run than your BMW 320d
The honest take. At 10,000 miles a year you'd save roughly £757 on running costs alone. That doesn't include the PHEV's purchase premium, depreciation or insurance — but it's the line that compounds month after month and the one no one tells you about honestly. Adjust the calculator below to your real annual mileage and your real home tariff.
What changes the answer most
- Annual miles. Higher mileage amplifies whatever the per-mile difference is. At 20,000 miles a year, double the saving (or double the loss).
- Your % on battery. 60% is a fair UK average if you charge at home overnight. People with a wallbox and short commutes regularly hit 80–90%.
- Your tariff. Off-peak EV tariffs (Octopus Go, Intelligent, OVO Charge Anytime) at ~7p/kWh are what make the maths work. On a 27p flat tariff the picture changes a lot.
Plug in your own numbers — both cars pre-loaded
Calculator opens with the BMW 320d and BYD Seal U DM-i side-by-side · 30 seconds · no card · save your numbers free