Is it still worth buying a petrol or diesel car in 2021?

After 2030, new petrol and diesel vehicles will no longer be legally available to buy in the UK, as the government aims to steer drivers towards more environmentally friendly cars.

But what if you're looking to buy a car this year? With nine years to go until that deadline, does it make sense to buy a petrol or diesel car? Or might now be a good time to start looking at electric vehicles or hybrids? 

To help you make your mind up, we asked three motoring experts to give us their opinions on the matter: BBC Top Gear's Paul Horrell, Wayne Robbins from new car retailer and Boundless partner Griffin, and Robert Llewellyn from the eco-motoring YouTube show Fully Charged...

What are the current advantages of buying a petrol/diesel car over an electric model? 

Paul Horrell: A combustion car may well suit you better if you drive either a lot of miles or very few. For low-mileage drivers, it’s mostly about economics. The higher cost per mile of a combustion car will easily be saved because they’re cheaper to buy. But there’s a green angle, too. It takes around 40,000 miles (estimates vary) to recover the extra CO2 used in the manufacture of an EV versus a combustion car.

Long-distance drivers want the convenience of petrol/diesel cars. These vehicles have a higher range between fuel stops, and refuelling is quicker than recharging. EVs are at their least efficient at motorway speeds. At 70mph, they only do about 70% of their WLTP range. So a ‘280-mile’ electric car would have to stop after less than 200 miles. And rapid recharging only works to about 80% of a full battery, which means they would have just 160-odd miles before the next stop. So a 500-mile motorway day, starting fully charged, would mean spending at least two hours at chargers.

Combustion cars, especially diesels, can tow bigger trailers and caravans. At the moment, there is no legislation enacted or planned that bans new Euro 6 combustion cars – petrol or diesel – from use in any of the UK’s city centres. Petrol and diesel are almost uniformly priced wherever you buy them. Electricity cost varies wildly, from about 15p/kWh at home to nearly 70p/kWh at some public points. That latter figure is dearer than petrol per mile. New diesels that meet latest standards save CO2 compared with petrols, and run cleanly. They’re a pretty good environmental choice for rural running where NOx emissions are of little concern.

For secondhand buyers, there’s much more choice with combustion cars.

Wayne Robbins: Petrol and diesel cars are not dead just yet. With all the media hype around electric cars, I think we can sometimes forget that even the most modern electric cars have some serious disadvantages over their fossil-fuel-burning cousins. As long as there is a need to effectively pull a caravan or horse trailer, or travel from one end of the country to the other in a day, there will always be a need for petrol or diesel cars. With their 60-80-litre tanks, and a filling station available every few miles, they represent reliable mile-munchers that can be replenished in 10 minutes. 

The latest breed of small petrol engines that have superchargers and turbochargers are also more economical than their larger CC forbears. Most now stop the engine while you are stationary, saving fuel and Co2/NOx emissions, while some even close down cylinders when coasting or breaking. 

Robert Llewellyn: There is only one advantage – it takes just 5-8 minutes to fill a petrol or diesel car up. Unfortunately, you have to drive to a filling station, stand outside as you pump a toxic, carcinogenic liquid into your tank while inhaling the fumes, then pay a lot of money for a product we import from benign (Norway) and not so benign (Russia and Saudi Arabia) countries, meaning vast amounts of money leave our economy. 

And what are the advantages of buying an electric car over a petrol/diesel model? 

Paul Horrell: Electric cars are responsible for less CO2. Although they take more energy and resources to manufacture, over their lifetime this is compensated for by lower CO2 output through driving. And actually, an electric car will become more CO2-efficient-per-mile-driven over the course of its life. That’s because the proportion of grid electricity that’s renewable is rising year by year. 

Unless (possibly even if) you’re a petrolhead, you’ll prefer driving an electric car. The power is delivered in an uncannily smooth, responsive and quiet fashion. Although they’re dearer to buy, they’re almost always cheaper to ‘fuel’, especially if you can recharge at home or at work. Also, servicing is cheaper. They avoid the London Congestion Charge, and in some places they can be parked free while they charge. 

If you have one as a company car, there are huge benefit-in-kind tax savings. If you have a garage or driveway, you can have a home charger installed. Often, these come free with a new car. If not, there’s a Government subsidy called EVHS. Then you can plug in overnight on cheap electricity, and every morning your car can be fully charged, warm and ready to go. 

Even the smallest-battery electric car will do 100 miles between charges. Most people very seldom do that in a day. And surely almost no two-car household does more than 100 miles a day in each of the cars.

Wayne Robbins: The obvious answer is the planet, but it goes a bit deeper than that. Electric cars are obviously cleaner for the environment as they have no emissions, but we still burn a considerable amount of fossil fuels to make the electricity to charge them, and also strip the planet of resources to build them in the first place.

If you average your mileage for the month and work out how much fuel you use, then compare this to the £70-£100 a month it takes to charge the average electric car, you'll find out if it'll actually save you money on fuel. However, the average electric car is around £6,000 to £10,000 more expensive than the equivalent petrol car, meaning you really have to build this into your overall lifetime costs. 

Robert Llewellyn: The people you drive past are not breathing in toxic gas coming out of your exhaust. They are easier to drive. They last longer and are cheaper to run. They are easier and cheaper to ‘refuel’. They accelerate faster, and as you slow down you recoup some of the energy you used to get moving.

Don't miss these other features on this subject:

• Buying an electric vehicle: everything you need to know

• What does the future hold for diesel-engined road vehicles?

• Is keeping my old car greener than buying a new EV?

What's your opinion on hybrid cars? 

Paul Horrell: This is complicated. First, non-pluggable hybrids. For town driving, they are smooth and quiet, and they cut emissions and fuel use by up to half versus pure petrol. That’s because the engine runs only when it is efficient to do so, and otherwise shuts down to hand over to the electric motor. But on motorways, hybrids hardly save any fuel compared with diesels.

Second, pluggable hybrids or PHEVs. For someone who commutes, and who can plug in at home or work, they’re a good choice both for cost and the environment. On the commute (say, 20 miles), they’ll use almost no fuel and emit nothing through the exhaust because they run on their battery. But for long trips, they can switch to the engine with its quick-refuelling advantages.

Also, the world is short of battery-making capacity, and batteries are CO2-intensive to produce. Hybrids have smaller batteries than EVs. So imagine there are four new cars. One full-battery EV entirely saves the CO2 emissions of one combustion car. But the other three are still pure-combustion, so among the four cars one quarter of the total fuel is saved. Now instead, share that same battery capacity among four PHEVs, where each of them halves their fuel use. The total fuel used is cut by a half, not a quarter.

So with any hybrid, plug-in or not, it’s essential that before buying you take a clear view on how you will use it. And also whether, if it’s a PHEV, you will regularly recharge it.

PHEV sceptics say they’re just a tax break. Well, they are a tax break – a very good one. But it turns out most PHEV drivers do actually plug them in, and see big fuel and CO2 savings.

By the way, PHEVs are not usually as nice to drive as full-electric cars in mixed driving, as the switching between petrol and electric can be a jerk.

Did I mention this is complicated?

Wayne Robbins: Hybrid cars are the perfect solution for those who do a lot of small journeys, but still need the assurance or capability of doing longer journeys without having to plan where they'll have to stop to recharge, as you often do with an EV. They represent a halfway house for those who mainly do a small run on a daily basis but still want the flexibility that a petrol or diesel car gives you.

Robert Llewellyn: Up to five years ago, hybrid cars played a central role in allowing people to experience what driving an electric car could be like. Now they are just combustion cars that are more complex and more expensive.

How easy will it be to sell a petrol/diesel car secondhand in the coming years? Will there be an impact on depreciation value? 

Paul Horrell: Many people say that because battery cars are a rapidly evolving technology, used ones won’t be worth much because they’re obsolete. People worry, too, that their expensive batteries with limited life will mean electric cars will be scrapped early, and that too will kill the value of used ones.

I strongly suspect the exact opposite. First, it’s about supply and demand. In 2019, pure-electric cars represented 1.6% of the new cars sold. In 2020, that figure was nearer 7%. In the next few years, that will rise further, and fast. Thing is, used car buyers will want electric cars for the same reasons as new car buyers. Especially because charging infrastructure is getting better, meaning that older, shorter-range EVs are becoming more useable not less. But where new electric car sales are growing, the supply of used electric cars will be limited. That’s because the proportion of three-year-old cars that are electric will always reflect the market share of three years ago, not the situation now.

The fears of degradation of electric-car batteries are over-emphasised. They’re not like phone batteries. They've proven to be very robust, they have good warranties, and they contain valuable minerals so have a recycling value.

Just as supply will affect used EV prices, it will affect combustion car prices too. Used diesel cars are losing value already because their new market is falling, meaning used ones are in over-supply. However, something might change closer to 2030. The ban is on petrol and diesel (not PHEV) new car sales. No ban is proposed on used ones. There will be some people who want those petrol and diesel cars. They won’t be able to buy them new, so might well pay firm prices for secondhand ones in good condition.

Wayne Robbins: The main changes to residual values for fossil fuel cars have already happened. We have seen a drop in large diesel car residuals over the past two years, but small diesel cars have been hit even harder. Gone are the days when the best used car to buy as a car dealer was a Golf TDI. They used to last two or three days on the forecourt before someone would snap them up. 
The best small car to buy today as a dealer is one powered by a 1.0-litre petrol engine. Small petrol and hybrid cars are king of the residuals at the moment, and we can’t see this trend changing any time soon. That said, there is still a need for large SUVs with a decent diesel or diesel/hybrid drivetrain. 

The one size of car that has hit the buffers is the Focus-sized car, but this is more to do with lifestyle changes than engine type. More and more people are moving to an SUV-type car, so the days of the Golf and Focus being the biggest sellers are over. This demonstrates that buying the right type of car is just as important as buying the right type of fuel for long-term residual value. 

Robert Llewellyn: I know very little about the intricacies of the secondhand market, but it’s going to be increasingly difficult to sell a secondhand combustion car, particularly a diesel one. Buying a new diesel today with the intention of selling it in three or four years is, I fear, going to result in great disappointment.

The government aims to encourage people to start buying electric cars before the 2030 ban. They've talked about punitive taxation on vehicles with higher emissions. What other measures should they consider?

Paul Horrell: The carrot: subsidise the installation of infrastructure. Not just rapid-charge points on major roads, but overnight plugs in residential streets. My local council is working with a Shell-owned company, Ubitricity, to install them in bollards and lamp-posts.

The stick: taxing fuel – even more than now – is the best way to divert people from high-emitting vehicles. Fuel poured into the tank is directly proportional to CO2 coming out of the exhaust pipe. With fuel tax, if people drive a more economical car, or drive more economically, or drive less, they’ll pay less tax.

It’s said that fuel tax penalises people who live in rural areas, or who have to drive for work or family reasons. Well yes, but in other ways, such as parking and insurance, car ownership is cheaper in the countryside. In extreme cases, there could be keyworker fuel-tax rebates.

Wayne Robbins: A total ban on all fossil fuel cars by 2030 is still reliant on the technology behind electric cars being good enough to give us all a car that will travel at least 300+ miles, and more importantly the infrastructure to power those electric cars.

At the moment, we are still a long way behind countries like Norway and Sweden in our infrastructure. They have charging points at almost every petrol station, as well as standalone electric parking spaces at shopping centres, and even EV-only car parks. Until we can sort out the issues around charging your electric car when you live in a block of flats or in a long, narrow terraced road, we will never be in a position to ban fossil fuel cars without grinding the country to a halt. 

Incentives also need to increase. By the nature of their build, electric cars are more expensive to manufacture, and as such cost the consumer more than a fossil-fuel car. The government's ‘up to £3,000 off an EV’ scheme is fine, but compare this to Norway, where there is NO VAT, NO road tax, and NO tolls or parking fees for electric cars, and we are again lagging behind in our intentions. Norway sold 73,890 new electric cars in 2020. Their electric car registrations were up by 27.3%, while diesel cars dropped by 46.7% and petrol cars dropped by 49.4%. Hybrid cars rose by 62.1% with just over 30,000 sold.

While any government wants to do the right thing, or say the right thing, reality can sometimes stop things happening.

Robert Llewellyn: The most obvious one is zero-emissions zones in cities, towns and villages. But they could also consider a long, slow and gentle process of education, illustrating all the externalities of using this fuel. Where does it come from? How much are we, as a nation, paying for it every day? What are the long-term consequences of continuing to use it, and what are the alternatives? Vast amounts of money are leaving our economy to pay other countries for this fuel, when we could produce ‘fuel’ (electricity) on these islands, creating thousands of jobs and bolstering our economy.

Given a choice, would you personally buy a petrol/diesel, an electric or a hybrid car right now?

Paul Horrell: Electric. For my rare holiday trips to the south of France, Spain or Italy, I’d take overnight charge stops on the way. Stopping over in a pretty French town with nice restaurants – that wouldn’t be so bad, would it?

Wayne Robbins: Would I buy an EV or hybrid? Yes. I actually run a Mercedes-Benz GLE 350de. I filled it up with diesel about four weeks ago, and plug it in every night to recharge. It's covered over 900 miles in the past four weeks, and I still have over half a tank of diesel. It's the perfect vehicle for my wife, who does a 20-mile school run with three children twice a day, but is also the ideal long-haul family car when we go away somewhere. 

We also run a VW ID3 and a Renault ZOE as company cars. These are fully electric cars and make perfect sense as cars for staff to use around town or for short trips to and from the sandwich shop. That said, we also have a five-year-old Mercedes-Benz GLS350 diesel auto, and a new Skoda Kodiak 2.0TDi 200ps auto. We use these for events around the country (in normal times). They carry huge amounts of kit and people, while pulling an events trailer at the same time – we wouldn’t change them for the world.

Should you buy an EV or hybrid? It really depends on your circumstances. The main things to consider, however, are:

• how many miles do you do, and what type of journey? If you do mainly short journeys to and from work or the bowls club, then an EV will work. If you do 100+ miles a day and need to tow a caravan, then no, buy a petrol or diesel car

• can you charge it? Charging an EV is vital. If it runs out of electricity, you are stuck. Charging normally needs to be done every day (usually overnight). Can you charge it easily on a driveway or in a garage? It’s probably the biggest overriding factor and will ultimately define your decision

• can I afford one? While we make owning a new EV easier with our discounts, they are still expensive. Is the extra money you’re spending really going to save you money in fuel with the type of journeys you do, or is ‘being green’ worth that extra money?

• do I trust an EV? There are fewer moving parts in an EV, but the biggest thing we hear from everyone is what happens when/if I run out of electricity? The plain and simple answer is: you stop. You will then need recovery from the AA or RAC. More than having trust in the car, you need to trust in yourself to plug it in every night, or your ability to work out where you can charge it on a longer journey

Robert Llewellyn: I've only driven 100% electric vehicles for the past 10 years, so I may be a bit unusual. However, I would never buy a combustion-engined vehicle, no matter what the configuration. I can’t be bothered with the endless maintenance and unreliability.

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