Should I buy a petrol or diesel car?

Lesson Type
Last updated: 3 Jun 2020

One thing that your driving lessons probably won't shed much light on is whether you should choose a petrol or diesel model for your first car. There are certainly a lot of reasons to consider diesel over petrol: cheaper tax, better residual value and better fuel efficiency to name a few.

Diesel fuel costs

Diesel costs more than petrol in the UK and although diesel is more efficient, it’ll take a lot of miles driving in a diesel car to make you any kind of impressive savings. Unless you plan to do in excess of 10,000 miles a year or intend to keep the same car for ages, petrol may actual work out as the cheaper option.


The generally superior efficiency of diesel cars means that they generally cost less to tax than their petrol-powered counterparts. A brand-new Fiat Punto 1.3 16v MultiJet Dualogic (diesel) costs £30 a year to tax. The petrol equivalent would cost you £135 a year. It’s a decent saving, but it’s not enough to allow most people to decide between petrol or diesel.


The differences in insurance costs for petrol or diesel versions of similar cars is negligible.

Diesel vs petrol servicing and upkeep costs

The servicing costs for diesel and petrol cars aren’t that different when you factor in the longer service intervals of diesels. There aren’t any big savings to be made here.


Eventually, you’re going to want to sell your car. Depreciation – the amount the value of your car naturally decreases during your ownership – can account for up to half of the total running costs of your car over a three-year period.

Diesels used to hold on to their value better than their petrol counterparts, when fuel prices seemed ever-increasing.

Environmental considerations

Diesels go for further on less fuel, that alone makes them better for the environment, right? Wrong. Contrary to how diesels were first marketed, they are actually more polluting than petrol cars. Although they produce less carbon dioxide, they produce more nitrogen oxide, a toxic emission which also forms the greenhouse gas nitrous oxide. Petrol cars also produce these gasses but use their three-way catalytic converter to reduce their volume.

So I should buy a diesel, right?

It’s a matter of personal preference; there’s no definitive answer to ‘petrol or diesel?’. Unless you’re planning on driving for more than 10,000 miles a year or keeping your car for a long time, you’re not going to make massive savings by driving a diesel.