It might not exactly be on trend to be talking about the dirty duo in 2022, but with prohibitive costs and lack of supply across both the electric and hybrid market, many drivers are continuing to turn to petrol and diesel as the choice for their next new or used car. This is naturally leading to people asking the age old question: petrol car vs diesel car -which is better?
Whereas diesel was once incentivised in the UK due to it emitting lower CO2 compared to petrol, in recent years the tide has turned as it came to light that the engines were emitting harmful nitrogen oxide pollution instead. This led to a turn in trends with petrol claiming most of sales and plug-in hybrid and electric cars increasing their share too.
Let’s look at some common questions when deciding which one is better for you…
Petrol car vs diesel car: which is cheaper to buy?
Diesel cars are generally more expensive to buy than petrols as the engines are more complex and require a high operating temperature. Furthermore, to reduce emissions and ensure compliance with EU laws they are also required devices such as AdBlue to be installed to ensure they’re as clean as possible.
On top of that, previous Benefit In Kind tax rates which favoured diesel now favour zero-emission driving, and Vehicle Excise Duty on new models no longer comes in cheaper than competitors either.
Winner: petrol
Petrol car vs diesel car: which is cheaper to fuel and maintain?
Diesel has historically been the more expensive fuel on UK forecourts, however with the recent rise in costs they’ve been at level-pegging for the first time in recent memory.
In spite of the cost, diesel engines are much more efficient over distance and so for motorists who cover long miles it works out cheaper in the long run thanks to impressive miles per gallon fuel consumption.
Petrol has traditionally been the cheaper fuel as it isn’t used across industries and vehicle-types the same way diesel has.
As far as maintenance, a report from 2018 on The Guardian stated diesel cars are more than three times as likely to break down as their petrol counterparts. This stat was based on analysis of 30,000 faults on three- to eight-year-old petrol and diesel cars over 12 months, with the average engine repair bill for a diesel being £517 compared with £433 for a petrol.
Winner: tie
Petrol car vs diesel car: which is cheaper to tax?
When diesel was being incentivised in the early 00s, the vehicles were lower to tax due to the low CO2 numbers. These categorisations have remained for these older models (despite paradoxically being more polluting than newer diesels) in spite of Vehicle Excise Duty being completely overhauled in 2017.
These changes saw the tax for cars registered from April 2017 dictated partly by their CO2 emissions, with motorists paying a large first year rate before the price defaulted to a standard rate for successive years.
In 2018 the chancellor announced that new diesel vehicles registered after 1 April 2018 that do not meet the real driving emission step 2 (RDE2) standard would be charged extra on their First Year Rate to the equivalent of moving up by one band.
The current Vehicle tax rates for 2021-22:
| CO2 emissions | Diesel cars (TC49) that meet the RDE2 standard and petrol cars (TC48) | All other diesel cars (TC49) | Alternative fuel cars (TC59) |
| 0g/km | £0 | £0 | £0 |
| 1 to 50g/km | £10 | £25 | £0 |
| 51 to 75g/km | £25 | £115 | £15 |
| 76 to 90g/km | £115 | £140 | £105 |
| 91 to 100g/km | £140 | £160 | £130 |
| 101 to 110g/km | £160 | £180 | £150 |
| 111 to 130g/km | £180 | £220 | £170 |
| 131 to 150g/km | £220 | £555 | £210 |
| 151 to 170g/km | £555 | £895 | £545 |
| 171 to 190g/km | £895 | £1,345 | £885 |
| 191 to 225g/km | £1,345 | £1,910 | £1,335 |
| 226 to 255g/km | £1,910 | £2,245 | £1,900 |
| Over 255g/km | £2,245 | £2,245 | £2,235 |
Petrol vs diesel car – which is better?
So with all this in mind, which is better? The fact is if you driving lots of miles and/or towing anything then diesel is still the best and most cost effective option for you. For those just making short infrequent trips then petrol is better.
With that said, both fuel types days are numbered: the government is banning the sale of petrol and diesel car sales from 2030 to encourage more motorists into zero emissions vehicle.
