If you’re in the market for a new car, the diesel v petrol debate won’t be far from your mind. Choosing the correct engine for your needs will save you money in the long run, and improve your enjoyment on the road.

There are obvious pros and cons with both, and this week we’re going to demystify them for you.

Diesel for economy?

If you’re a heavy motorway user who finds their clock ticking over at an alarming rate, then it’s still a good idea to invest in a modern diesel. Yes, running costs are a little higher, but for consistent motorway driving, a decent diesel engine will still give you greater economy over a three year period.

You’ll pay more for your diesel version of the same car, but it’ll depreciate in value less too because the market for used petrol engines is much weaker – and it’s likely to be cheaper to insure!

Petrol for performance?

The feeling of the low rev torque a diesel engine gives you may be useful for motorway overtaking or towing, but when it comes to real performance, petrol still leads the way by some margin. Yes, they’re thirstier, but if you’re looking at hot hatches or sports cars, fuel economy is probably going to be pretty low on your list of priorities.

The wider power band and free-revving nature of a petrol engine lends itself to fast cars, and there’s no doubt that the roar of a V12 is impossible to replicate with a diesel!

Buying used

The diesel v petrol discussion becomes much more complicated when you’re buying used. Many second-hand diesels are high mileage motors that, at first glance, appear to be bargains – but the reality is that there’s a high chance of an expensive bill around the corner.

Modern diesels come with both diesel particulate filters (DPFs), and dual mass flywheels (DMFs) – fitted to improve emissions and reduce vibrations common with older diesel engines. DPFs need regular periods of higher speed driving to self-clean, and DMFs are a known weak point – especially if the car is regularly driven in traffic with poor clutch control. If either of these parts go on you, you’re looking at a bill of several hundred pounds, so be aware of this when buying.

Petrol motors, on the other hand, have neither of these issues, so buying used should be less of a gamble.

There’s no right or wrong in the diesel v petrol debate, but it’s important to know the pros and cons of both before deciding which is best for you.