Mercedes C300e running costs in the UK
How much does the Mercedes C300e actually cost to run? Forget the 313 MPG brochure number — that figure assumes you start every trip with a full battery and only count the petrol miles. Here's what it really costs at UK 2026 prices, 10,000 miles a year, 60% of miles on battery.
Mercedes C300e — at a glance
| Year | 2024 |
|---|---|
| Battery | 25.4 kWh |
| WLTP electric range | 70 miles |
| WLTP combined MPG | 313 mpg (brochure figure — see below) |
| Real-world petrol-only MPG | 50 mpg (once the battery's empty) |
The real annual cost
Total running cost / year
£707
7.1p/mile blended · 10,000 mi/yr · 60% on battery
Breakdown
| Battery miles (60%) | 2.3p/mile · £140/yr |
|---|---|
| Petrol miles (40%) | 14.2p/mile · £567/yr |
| Break-even fuel price | petrol would need to drop to £0.26/L for it to be cheaper than home off-peak charging |
vs a typical UK petrol car (40 mpg)
| 40 mpg petrol car | £1,772/yr (17.7p/mile) |
|---|---|
| Mercedes C300e | £707/yr (7.1p/mile) |
| Annual saving | £1,065 (60% cheaper) |
The honest take. The Mercedes C300e is 60% cheaper than a typical petrol car at these assumptions. The number that matters is your number — your old car's MPG, your tariff, your annual mileage, and how often you actually plug in. Plug your own figures into the free calculator below and you'll see in seconds.
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