Diesel, petrol, electric or hybrid? How do I choose?

Talking you through the motive power choices of the 2020s and which is best for you.

Here are the four main methods of propulsion in modern-day cars, and which driving styles they suit the best, to help you make the right choice on your next new motor.


Buy it if: you do well over 20,000km per year and very few short urban or semi-urban journeys

Don’t buy it if: you drive short distances regularly, often into the middle of towns and cities

Try not to be put off diesels by recent press coverage. The Volkswagen Dieselgate saga and focus on NOx emissions have seen sales of diesel cars reduce in Ireland in recent years, but this is still a viable fuel source – especially if you’re a long-distance driver, where it remains the best option all round. Brand-new diesels are among the cleanest cars going, as manufacturers have to meet stringent emissions laws on particulates and other pollutants, and it’s only really older diesels that are going to get hammered financially in the coming years. The rough rule of thumb in our industry says that if you do well over 20,000km per year, diesel remains the best choice – it’s as simple as that. Oh, and don’t buy a car with a diesel particulate filter (DPF, and almost every diesel of the past 15 years has one of these things fitted) if you regularly do short journeys; the DPF needs to get hot and be run at motorway speed to ‘recycle’ and, if it doesn’t get this often enough, the DPF clog ups, requiring an expensive fix.


Buy it if: you do less than 20,000km per year but still spend some of your time on the motorway

Don’t buy it if: you do a lot more than 20,000km per year and there’s a good turbodiesel alternative available

Petrol cars have come on leaps and bounds in the last decade or so, managing to close the once-huge gap in economy between themselves and equivalent turbodiesels. That said, they’re still not the sensible option if you do well over 20,000km per year, but any figure below that and these could be the choice for you. They’re still best used for out-of-town driving, so if you live on the edge of one town or city and you work daily in another conurbation that’s 50km away, pick a petrol every time. However, mainly urban and semi-urban drivers will probably be better off with one of the two choices below…


Buy it if: you’re an urban or semi-urban commuter during the week, and at weekends you travel hundreds of kilometres to visit far-flung family members

Don’t buy it if: you’re on the motorway all the time, or you don’t have access to a charging point at your home address/place of work

We are viewing this section as plug-in hybrids, which typically team a petrol engine with a decent-sized lithium-ion battery and electric motor to provide (usually) around 50km of all-electric driving range; mild hybrids, which only augment an internal combustion engine, or full hybrids, like most of the Toyota and Lexus models that don’t feature plug-in capability, are best treated in a similar fashion to petrol vehicles, though the latter are great in and around town.

So, plug-in hybrids: they’re excellent, if you’re going to regularly charge the battery up using mains electricity. You can charge a plug-in hybrid’s internal battery from the onboard combustion engine, but this leads to poor fuel economy, because the engine is then forced into doing two jobs at once – it is propelling a heavy vehicle along AND it is charging a large lithium-ion battery pack. Therefore, it’s the mains charging that is key to a plug-in hybrid’s success. A great example of a plug-in hybrid user is someone who lives on the edge of Dublin and who works in the city. They drive into work on electric power each day, having charged their plug-in hybrid at home overnight, then they plug it in while at the office so that they can drive home on electric power. At weekends, though, they go off to visit family in Cork on a regular basis and a full electric car might not cut it for that journey. If this sounds like you (and no, you don’t have to live in Dublin, that was just an example…), get yourself into a plug-in hybrid.


Buy it if: you are a mainly urban driver who conducts lots of short journeys per week, and you have good access to high-speed public and private charging points

Don’t buy it if: you do more than 20,000km per year, all of which are done on motorways, or you’re on a tight budget

The future of motoring but, at the moment, the battery technology is not quite there in terms of providing petrol- or diesel-like cruising range on a purely electric vehicle (EV). This brings in the oft-heard concern of ‘range anxiety’, which is what a lot of people fear about electric cars: running out of battery power at the side of the road somewhere, kilometres away from a charging point. Thus, while there are electric cars that can now do 400km and more on a single charge, we’d still recommend EVs to those who are mainly urban or semi-urban drivers. In which case, they’re brilliant. The instant torque of them and super-low running costs brought about by low taxation requirements make EVs fantastic city vehicles, no matter how physically big they are. The key to an electric car is access to the charging infrastructure: fast, 50kW-plus direct current (DC) chargers makes recharging even the biggest lithium-ion battery a matter of tens of minutes, rather than tens of hours, so that the practicality is there for daily commuters.