Cupra Formentor e-Hybrid vs Mercedes C300e: which is cheaper to run?
Both are plug-in hybrids; both look attractive on the brochure. The interesting question is how much one costs you over a real year of UK driving — at your tariff, your mileage and your charging habits. Here's the honest side-by-side at typical UK assumptions.
| Spec | Cupra Formentor e-Hybrid | Mercedes C300e |
|---|---|---|
| Battery | 13 kWh | 25.4 kWh |
| WLTP electric range | 33 mi | 70 mi |
| WLTP combined MPG | 188 mpg | 313 mpg |
| Real-world petrol-only MPG | 42 mpg | 50 mpg |
Annual running cost (10,000 mi · 60% on battery)
| Cost | Cupra Formentor e-Hybrid | Mercedes C300e |
|---|---|---|
| Battery £/mile | 2.3p | 2.3p |
| Petrol £/mile | 16.9p | 14.2p |
| Blended £/mile | 8.1p | 7.1p |
| Annual cost | £815 | £707 |
| Break-even fuel price | £0.22/L | £0.26/L |
Annual running cost difference
£108
The Mercedes C300e is roughly £108 cheaper a year (13%) at these assumptions.
The honest take. On running costs alone, the Mercedes C300e is the cheaper of the two at typical UK numbers. But running cost is only one variable — purchase price, finance, tax, insurance and depreciation usually swamp it. Use the free calculator below to plug in your own annual mileage, your home electricity tariff, and what % of your driving you'll realistically do on battery. Two minutes and you'll know which car is actually cheaper for your driving.
Run your own numbers — both PHEVs pre-loaded
Calculator opens with the Cupra Formentor e-Hybrid and Mercedes C300e side-by-side · adjust to your miles and tariff · save your comparison free