Here's how to decide between a petrol and diesel engine, according to an expert

Niall Cotter, general manager at Blackwater Motors weighs in on a tricky choice.

FINDING THE RIGHT car for your needs, lifestyle and budget can be a tricky process. We want to help streamline the search. As part of our Insights series, every week we’ll take a different car-buying question to the experts at the heart of the motor industry.

This week, we asked Niall Cotter, general manager at Blackwater Motors for his insight on a tricky choice for anyone sussing out a new car: should I go for diesel or petrol?

What should I know about diesel engines?

shutterstock_284650535 Shutterstock / Gubin Yury Shutterstock / Gubin Yury / Gubin Yury

1. They’re fuel-efficient for frequent drivers

Although diesel cars are more expensive, you’ll get more miles out of the fuel that you do buy (and diesel is currently around 10c cheaper), so they’re definitely more fuel efficient. If you have someone doing 40,000 – 50,000 kilometres per annum they’re a lot cheaper.

2. …But they’re more expensive to maintain

Maintenance on a diesel engine is definitely more expensive – it’s a more complex engine so it can take longer to fix and the parts can be more expensive. Plus, if you’re using a diesel for short journeys the filter can get blocked which isn’t covered by warranty. It’s important to choose the right type of engine for the miles that you do.

3. Some say diesel engines are worse for the environment

We were originally told that diesel was a cleaner fuel, but current studies would say the opposite is true and that petrol is less harmful than diesel.

What should I know about petrol engines?

shutterstock_470069273 Shutterstock / vectorfusionart Shutterstock / vectorfusionart / vectorfusionart

1. They’re becoming more popular

There’s definitely a shift towards petrol cars, it used to be a divide of about 75/25 diesel to petrol but nowadays it’s closer to 50/50. There’s been a lot of negativity in the press in relation to diesel emissions which has affected diesel’s popularity.

2. They’ll suit people who use their car less

If someone is driving 10,000 – 12,000 kilometres a year, you could definitely make an argument that a petrol engine is more viable because you don’t need the fuel efficiency of a diesel engine. Petrol cars would be more likely to suit people doing a lot of city driving and short journeys.

3. The resale value of petrol-fuelled cars is improving

Historically, diesel cars had a better resale value, but the resale value of petrol cars is increasing from what it was years ago. Demand is higher now for petrol cars, so people are willing to pay more.