Petrol vs Diesel Cars - Which is the Cheapest to Insure?
Generally, diesel-powered cars tend to be more expensive to buy than petrol cars, with diesel vehicles typically costing between £1,000 and £2,500 more than their petrol equivalents.
As a result, diesel cars usually cost more to insure because insurance companies factor in the extra expense they would have to pay out in the event that your car is stolen or written-off, not to mention the fact that parts and repairs will cost slightly more to replace.
However, diesel cars have traditionally held on to their value for longer than petrol cars, as diesel engines tend to last longer. Therefore, if you think you will be selling your car in a few years then you may well get a better resale price on a diesel car than a petrol model.
This could change though, as there are now more and more restrictions coming into effect on diesel cars, as they are much worse for the environment, so it’s not yet certain how well they will retain their value in the long-run.
Vehicle tax and other charges
The laws on road tax for petrol and diesel cars have changed recently. Prior to 2017, vehicle taxes were worked out based on CO2 emissions, which meant that diesel cars were taxed at a lower rate as they produce less CO2.
Since 2017, though, both petrol and diesel cars have been taxed at a standard rate of £140 after their first year – meaning after the initial year, you will no longer pay lower taxes on a diesel car than a petrol car. This only applies to cars registered on or after 1 April 2017 - if your car was registered before that date then you will still pay tax at the old rate (adjusted in line with the Retail Price Index).
Another factor to consider is the restrictions and charges applied to diesel cars in some areas of the UK.
Since 2019, the Ultra-Low Emission Zone (ULEZ) in London has required all cars in central London to meet the Euro 4 emissions standard - If not, they will have to pay a charge of £12.50 per day. Most modern petrol cars meet this standard, but most diesel cars registered before 2015 do not, so they will be required to pay the charge.
There are plans to expand the ULEZ to other major cities including Birmingham and Glasgow in the coming years, so diesel drivers across the country may face similar charges.
Do diesel cars pollute more than petrol cars?
Although diesel cars produce less CO2 overall than petrol cars and are slightly better for the environment in terms of climate change, they also emit far more dangerous chemicals that are toxic for humans – which makes them worse in cities.
Diesel engines are more fuel-efficient than petrol equivalents and for many years, they were seen as a greener alternative to petrol cars, so much so that the government introduced incentives to encourage motorists to choose diesel cars over their petrol counterparts.
In recent years, however, new studies have complicated this as they discovered that diesel engines produce far more nitrogen oxide than petrol engines. They also produce a lot more particulates, which are very small pieces of soot leftover from the combustion process and a very major health hazard.
To reduce this risk, car manufacturers have begun to fit diesel cars with particulate filters to reduce the emissions – with some claiming that new models are now cleaner than some petrol cars.
Hybrid and electric alternatives
Hybrid and fully electric cars are becoming an increasingly popular alternative to both petrol and diesel cars as they are much better for the environment. They are also taxed at a significantly lower rate and are exempt from congestion charges. However, they are still usually more expensive to buy than petrol and diesel cars.
By 2035, or even 2030, all sales of new petrol, diesel and hybrid vehicles will be banned and new cars and vans will be required to have a plug-in hybrid or electric engine.
So, which is the cheapest to insure? - Petrol or diesel?
After taking all of the above points into consideration, it is easy to understand why insurance for vehicles with diesel engines costs more than the price of insurance for petrol vehicles.
Whatever vehicle you choose to buy, whether it's petrol, diesel, hybrid or electric, it is always worth doing your research and comparing quotes online by using a few different comparison sites, as this is the only way to get the best car insurance deal on the market.
Compare quotes now at no obligation to see how much you could save on cover: