Petrol, diesel or electric?

Choosing the appropriate fuel

How to Decide Between A Petrol, Diesel or Electric

If you are looking at the automotive landscape right now, you could be forgiven for thinking that electric is the only fuel choice for your next vehicle. And essentially, you'd be correct, but for some, the most obvious choice might not be the best one. Here we look at why you would lease electric and why you may still consider an internal combustion engine (ICE).

A decade or so ago, the decision as to what fuel to choose was straightforward. If you made a lot of long-distance trips and drove over ten thousand miles a year, you would pick a diesel car. It was petrol if you made many start-stop journeys and typically did less than eight thousand miles a year. Simple.

Over the decades, new technology arrived to help lower emissions and help the green credentials of many car manufacturers. Direct fuel injectors, catalytic converters and diesel particulate filters were invented to help Internal Combustion Engines (ICE) cars remain valid in a rapidly heating world.

After a while, manufacturers like Toyota, with their Prius, added electric drive trains to ICE cars to help drive emissions down further and increase efficiency.

Diesel cars, filters and urban driving

Since 2009, diesels sold in Europe have included a Diesel Particulate Filter (DPF), which is part of the vehicle's exhaust system. This filter traps "soot" created during the regular operation of the diesel engine.

In order to meet European legislation, all vehicle manufacturers fit a filter to clean up exhaust gasses. Hence, the days of black smoke blowing from diesel exhausts become history.

However, for the DPF to work correctly, it has to heat up enough to burn off trapped soot particles. If you drive on A-roads, motorways or dual carriageways at speeds above 40mph, the filter can work in 10 minutes.

Make only short journeys at low speeds. The filter will not reach a temperature to remove soot and 'regenerate' or clean itself. So most manufacturers recommend that you drive a diesel car for 10-15 minutes at speeds above 40mph from time to time so that the filter cleans itself before any problems arise or a warning light appears on the dashboard.

Your weekday driving habits - when you are doing school runs and driving to and from nearby work - are different from weekends. Then, you may visit relatives and friends, or drive on faster roads on shopping trips - so if this is your driving routine, the filter can regenerate and clean itself.

It's important that you follow handbook instructions to regenerate the diesel filter, as the cost of cleaning or replacing the filter at a garage would not be covered under the vehicle's warranty - and these costs are high. So if you only drive on short journeys or live in a busy city, an EV or petrol car might suit you better

Hybrid engines offer even better economy

Whether diesel or petrol power suits your typical journeys best, a hybrid might be a good idea. A hybrid system stores energy generated during braking and deceleration in a rechargeable battery, which is then used to power the car instead of burning fuel, improving economy.

A bonus is that hybrids typically achieve their best fuel economy for city driving. For example, the Toyota Yaris, urban cycle gives 91mpg, 11mpg above its extra urban mileage figure. So for city drivers, a petrol hybrid could be the intelligent option.

Electric Powered CARS

Now more than ever, electric vehicles are becoming increasingly important. An electric car is the same as a standard car, only powered purely by electricity. They have a large battery pack that must be charged regularly, like would fill your fossil-fuelled car (only usually a lot slower).

The benefits of these are that they are deemed zero-emission, as there is no exhaust. They can also be very powerful in comparison to their fossil fuelled-powered counterparts. In the earlier years of electric cars, their perceived drawback was that people could get 'range anxiety', fearing they would run out of charge before getting to a charge point or home.

Nowadays, modern EVs can tell you where the charge points are, reroute towards them, and, of course, have much longer ranges. Check out our Electric Vehicle Hub for more information.


Read more about Diesel Particulate Filters (from the AA)