Petrol, Diesel, or Electric: Which is best?

Contents: 

• Petrol cars pros & cons
• Diesel cars pros & cons
• Hybrid cars pros & cons
• Plug-in hybrid cars pros & cons
• Electric cars pros & cons
• Petrol vs Diesel cars
• Petrol & Diesel vs hybrid cars
• Hybrid vs plug-in hybrid cars
• Hybrid cars vs electric cars

For many years, there were basically only two methods of fuelling cars in the UK: diesel or petrol. But, over the past decade, we’ve started seeing several new methods of powering vehicles appear, with a shift towards more eco-friendly energy sources. That said, only about 3% of the UK fleet was powered by anything other than petrol or diesel in 2020 according to the ONS. 

Nowadays, it’s no longer just a question of a petrol or diesel car – you can add in various forms of hybrid, plus electric vehicles to your list (we’ve excluded things like hydrogen-powered engines, since they aren’t widely available in the UK yet). 

It’s great you’ve got more options, but at the same time, all that choice can be pretty head-spinning! But have no fear, Motors’ experts are here to guide you through your options. 

What are the different ways to power a car?

For most of the last 100-odd years, diesel or petrol have been the main fuels used to power practically all cars. We get them by distilling crude oil. It’s then a case of putting the fuels into your car engine, igniting them with a spark, and hey presto – you can drive! 

However, it’s become increasingly clear that diesel or petrol cars are damaging the environment through their emissions of carbon dioxide. What’s more, there’s a limited supply of oil in the ground, so eventually we’re going to have to find an alternative. 

All this means that various ‘new’ methods of powering cars are catching on. Let’s look into each of them, to see their pros and cons, and how they work. 

Petrol cars pros & cons

Petrol cars have traditional combustion engines which you fill up with petrol. The fuel is ignited with a spark and that powers the car. They’re by far the most popular kind of car and of the ~ 32 million cars registered in the UK at the end of 2021, just under 19 million are powered by petrol (according to the RAC Foundation). 

Diesel cars pros & cons

Diesel cars are powered with diesel which you can fill up with at many pumps around the country. They’re similar to petrol vehicles, but diesel engines ignite the fuel by using air compression – not a spark. Traditionally this type of vehicle tends to be more fuel-efficient than petrol counterparts.

Diesel cars are the second most popular way to fuel a car in the UK – they made up about 36% of cars on the road in 2021 according to the RAC Foundation’s figures.

Hybrid cars pros & cons

Hybrid cars are vehicles that combine a battery pack and a petrol engine which can be used separately or at the same time. That means they can reduce emissions while keeping good mileage and speed (they still emit some CO2 and other gases). 

Hybrid cars are a good choice if you’re environmentally conscious but cannot commit to a fully electric car just yet – either because there is no easy way for you to charge the batteries, or you need to cover long distances regularly. In these circumstances hybrids are ideal.

There are three different types of hybrid vehicles that you can choose from:

• Full hybrid: This is the most common type of hybrid vehicle. They use both a combustion engine and an electric motor to power the car either simultaneously or independently from each other. For example, they can go fully electric for short distances at low speeds in an urban setting or switch to faster speeds and longer distances using the petrol engine.
• Mild hybrid: These vehicles use a combustion engine and electric motor together, and never independently from each other. This is because the electric motor only assists the engine. For t his reason, they are not as fuel-efficient as full hybrids, nor as eco-friendly. But they are the cheapest way to own a hybrid. 
• Plug-in hybrid electric vehicles (PHEVs): Plug-in hybrid cars are like an electric car, in that they have a big battery that you can charge up by plugging in at a charging point and you do most of your driving using the battery. However, they do also have a small petrol engine which you can fill up if needed – which means you needn’t fear running out of battery. PHEVs deliver a much better electric-only range than other hybrids.

Read about our top 10 PHEVs for sale today to see all the options available.

Electric cars pros & cons

Electric vehicles (EV) are cars that are powered purely by a built-in battery and electric motor, instead of the combustion engine that petrol, diesel and hybrid vehicles use. The battery pack can be charged using a special cable, either at home, work or any of the thousands of charging points in the UK.

Electric cars are the new kids on the block and some people may feel a bit less confident about them. But there’s plenty of great reasons to give EVs a chance. Check out our electric cars section for more in-depth insights.

Now we’ve got up to speed with all the main fuel types, let’s compare them to help work out which might be right for you.

Diesel or petrol – which is better?

So, you’ve narrowed it down to a diesel or petrol car. Which might be the right one for you? Here are some key points to think about:

• Environment: Overall, petrol engines are less fuel-efficient than diesel ones but they do produce fewer particle emissions. It’s true that diesel cars produce less CO2 than petrol, but diesels do emit more harmful particles such as nitrous oxide and other particulates. Overall, this makes petrol cars a little kinder to the environment.
• Driving needs: Petrol cars are perfect for driving short distances in urban environments, although if you take them on the motorway they’ll still do great. Meanwhile, diesels tend to be more fuel-efficient than their petrol counterparts, but they do need long runs to clear their particulate filters which can become clogged with repeated short journeys. This makes them ideal for drivers who need to commute long distances or drive a lot of miles regularly. If you want a big car or a family car, then diesels might also be a better choice since they tend to have bigger towing power (handy when you have to carry heavy loads).
• Long term outlook: Thinking long term about what’s better, petrol or diesel, you could consider how easy it’ll be to sell the car too. Broadly speaking, petrol cars are more popular so you might just find it easier to sell further down the line. That said, with diesels emitting less CO2, they might have a longer shelf-life considering the government’s plans to phase out carbon-emitting cars.
• Cost: By and large, diesels are more expensive than petrol cars, so petrol is the best choice if you’re looking to save money. And, diesel itself is quite a bit more expensive than petrol. 

Petrol & Diesel vs hybrid cars

If you’re trying to choose between petrol/diesel or a hybrid car, then take the following factors into account:

• Environment: Hybrid cars are usually a better option for the environment, although a mild-hybrid only performs slightly better in this respect than a highly efficient modern diesel or petrol. 
• Driving needs: Hybrid cars are often viewed as ideal city cars – they have low emissions, so you may pay less for driving around cities, and their batteries recharge when you brake (which is inevitable when driving in town). But if you’re looking for something that can take you on frequent, long-distance trips or for motorway driving, petrol and diesel will be a better choice. 
• Long-term outlook: The resale market for all these cars is healthy, but it’s probably best for hybrids (though remember the sale of new hybrids will also be stopped from 2035).
• Cost: Petrol and diesel cars tend to be cheaper than hybrids but buying a used hybrid can be a great way to get an electric car for less

Hybrid vs plug-in hybrid cars

You’ve decided to go electric. But how do mild and full hybrids compare with PHEVs? Let’s see:

• Environment: PHEVs allow you to drive further using just the battery, so they in theory emit less CO2 over their lifetimes than other forms of hybrid. 
• Driving needs: All types of hybrid (including PHEVs) are fairly comparable in terms of driving style. They’re all good city cars, but will struggle more with extensive motorway driving. That said, mild hybrids and full hybrids do offer better range overall since they have bigger petrol engines. 
• Long-term outlook: The resale market for all these cars is healthy and pretty similar as EVs become more and more popular.
• Cost: Mild and full hybrids have been around a lot longer than PHEVs, so they tend to be cheaper.

Hybrid cars vs electric cars

Want a future-ready car that causes less damage to the environment? Let’s compare EVs and hybrids:

• Environment: Since EVs don’t produce any direct emissions, they beat hybrids when it comes to environmental considerations. 
• Driving needs: Both are great city cars, thanks to their use of battery power and the fact that braking helps recharge them. If you plan to do longer drives on a regular basis, you’re probably going to want to opt for a hybrid though – the fact you can still nip into any petrol station and fill up means you avoid the dreaded ‘range anxiety’. But it depends – some EVs (namely, Teslas) have extensive rapid charging networks around the country which even let you charge for free (within certain limits). 
• Long-term outlook: The resale market for all these cars is healthy and pretty similar. Since the government plans to ban the sale of new hybrids from 2035, the outlook for EVs seems the best.  
• Cost: All forms of hybrid car are quite a bit cheaper than comparable EVs. But remember, you’ll pay no road tax or fuel duty with your EV and charging is cheaper – so they could be less expensive in the long run. Plus, you’ll save on petrol/diesel costs. 

Summary

Phew! We appreciate that’s quite a bit of information to take in when you’re comparing petrol vs diesel cars, or hybrids vs EVs. Ultimately, the decision will come down to what you need the car for, where you live, and how concerned you are about your own carbon emissions –  although running costs and resale value should also come into consideration. 

There’s a lot to think about, but armed with the right information, the decision will hopefully be a little easier. So, which will you choose? 

Sources

[1] Trading Economics – United Kingdom Gasoline Prices
[2] Yahoo!Finance – High Fuel Prices To Persist into 2023
[3] AutoExpress – UK Fuel Duty in Line for 23% Hike in 2023
[4] Autocar – Under The Skin: Why Diesel Engines Will Always Be More Efficient Than Petrol 
[5] Heycar – Latest Petrol and Diesel Fuel Prices
[6] Sky News – Three of our Four Electric Vehicle Owners Unhappy