At a glance

  • When powering a car today, there are more methods available than ever
  • Petrol and diesel are still most common, but hybrid and electric are becoming more popular
  • Read tips on comparing petrol vs diesel cars and the other options available
  • We look at the pros and cons of each - including things like costs, the environment, and resales


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). 

Petrol Car Pros:

By far the widest range of models available
Ever improving fuel-efficiency
Lower tax than a diesel car
Extensive petrol station network makes refuelling a breeze
Familiarity - most people will have learned to drive a petrol car

Petrol Car Cons:

The price of petrol has been increasing over the past few decades, hitting record highs in 2022 following Russia’s invasion of Ukraine [1]
What’s more, these eye-watering pump prices are expected to continue in 2023 [2]
From spring 2023, the UK government is expected to hike fuel duty on petrol by a whopping 23% [3]
They produce carbon emissions and other forms of air pollution, which are contributing to the climate crisis
The government is banning the sale of all new petrol (and diesel) cars from 2030, so their days are numbered
Oil is clearly a finite resource
Petrol vehicles depreciate faster than diesel ones

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.

Diesel Car Pros:

Tend to depreciate less than petrol cars
Good for driving longer distances
More fuel-efficient than petrol cars [4]
Higher pulling power than petrol cars on average – makes them ideal for large cars and SUVs or for towing a caravan
They tend to have lower CO2 emissions than petrol cars
Easy to refuel thanks to extensive network of petrol stations which have diesel pumps too
Most have better resale value than petrol (but not always)

Diesel Cars Cons :

Historically more expensive to buy
Affected by the same fuel price volatility as petrol cars, with diesel now by far the most expensive fuel [5]
Produce polluting particles like nitrous oxides, hydrocarbons and particulates – so while CO2 emissions might be lower, they’re hardly a ‘green’ option
On average higher insurance costs
Tend to cost more to replace or repair
Oil is a finite source of power
Engines tend to be noisier than petrol or other kinds of car

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.

Mild and Full Hybrid Cars Pros:

Cleaner and more fuel-efficient, particularly in urban environments
High resale values
Pay less road tax than diesel or petrol cars (depending on emissions)
No range limits thanks to the conventional engine
A smoother, quieter ride than diesel or petrol

Mild and Full Hybrid Car Cons :

Generally more expensive than petrol or diesel cars
Emit more emissions than a pure electric vehicle
Expensive to repair
Lower driving power than diesel and petrol cars due to generally smaller engines
You’ll still pay more road tax than a pure EV, and will also pay fuel duty whenever you fill up
Less efficient during colder weather

Plug-in Hybrid Car (PHEV) Pros:

Lower emissions than other hybrid cars
Pay less road tax than other hybrids
No range limits thanks to the conventional engine
A smoother, quieter ride than diesel or petrol
Like owning an EV, but without the same range anxiety issues

Plug-in Hybrid Car (PHEV) Cons:

Generally more expensive than regular hybrids
Emit more emissions than a pure electric vehicle
You no longer benefit from congestion charge exemptions in London (while pure EVs still do)
Plug-in hybrids require charging infrastructure and can take hours to recharge
Expensive to repair
Reliant upon often underpowered engine when electric power runs out
You’ll still pay more road tax than a pure EV, and will also pay fuel duty whenever you fill up
Less efficient during colder weather

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.

Electric Car Pros:

Minimal running costs - an off peak full charge could cost as little as £3-4
Environmentally-friendly - if the charger you’re using is powered by renewable energy, your driving could technically have zero carbon emissions
An almost silent drive without any excessive engine noise
Zero road tax, congestion charges or ULEZ charges - saving you hundreds of pounds per year - although this is likely to change in the future
Instant acceleration - EVs can be impressively fast pulling away from traffic lights and roundabouts
Can charge overnight, ready for the morning
Their range is continually improving, with new technological advances every year
Since they’re powered by a fairly simple battery engine, there’s much less than can go wrong compared with a combustion engine
Conveniently recharge at home or on your street - without needing to drive to a forecourt
The UK government is clearly signalling that it sees EVs as the future of mobility, so why not get ahead of the game?

Electric Car Cons:

They generally have a higher price tag than all other comparable cars
Range remains an issue - you will always depend on having to find a charging point, and that can reduce spontaneity on road trips, and add in the famous ‘range anxiety’
Some models can still take quite a long time to recharge - and any full charge takes much longer than filling up with petrol or diesel
Although the UK’s charging network is constantly expanding, coverage is still patchy, especially outside major cities
There have been numerous stories in the media about EV owners feeling frustrated with the reliability of the public charging network [6]
Electricity might still be generated by fossil fuel power stations, so they’re not always as green as they seem
At some point in future, it seems likely the government will start to introduce various forms of road tax for EVs

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. 


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?