Petrol, Diesel, Hybrid or Electric: What's Best for a First Car?
Petrol is the mainstream first-car choice and usually the lowest insurance group for the same model. Diesel and hybrid trade a higher average group for better fuel economy, which suits higher-mileage driving more than typical new-driver use.
This isn’t a question with one right answer, it depends on how the car will actually be used, particularly the annual mileage.
The detail
By fuel type:
| Fuel type | Average insurance group | Average mpg |
|---|---|---|
| Petrol | 10 | 54 |
| Diesel | 12 | 65 |
| Petrol hybrid | 15 | 69 |
Petrol dominates the first-car market by a wide margin, and it also averages the lowest insurance group of the three. Diesel and hybrid both average better fuel economy, but at a higher typical group, meaning the fuel saving needs enough annual mileage behind it to be worth the higher premium.
Electric cars are a smaller part of the first-car used market on our current data, too small a sample here to average meaningfully, so check the specific car’s insurance group, real-world range and public charging costs in your area individually rather than relying on a general rule.
What this means for your first car
For typical new-driver mileage (assuming 8,000 miles a year), petrol usually wins on total cost: the insurance saving from a low group outweighs the smaller fuel bill a diesel or hybrid would offer at that mileage. Diesel starts to make more sense at meaningfully higher annual mileage, where the fuel economy gap does more work. Hybrid sits in between, and is worth checking model by model since the group premium varies more than the mpg gain always justifies.
First Car Scout shows the insurance group and full running cost for every fuel type in your search results, so you can compare a specific petrol, diesel or hybrid car rather than relying on the general pattern.