Petrol vs Diesel

Petrol and diesel both have their benefits and both will provide different perks to people. While there is no clear winner, we’ve outlined below some of the things to bear in mind when choosing your next car. Bear in mind that laws and regulations change quickly so while this information is up to date, a law might be introduced in three years that will affect your choice now.

Car tax

After the dieselgate scandal of 2015, the UK government introduced stricter tax rules for diesel cars that don’t meet the Real Driving Emissions 2 (RDE2) standard. Any diesel car that doesn’t meet the standard pays up to 4 times more in their first-year payment than a petrol or diesel that does meet RDE2. For example, if your diesel that doesn’t meet RDE2 and emits between 51-75 g/km of CO2 you’ll pay £105 but if it does meet RDE2 or is a petrol, for the same CO2 emissions, you’ll pay £25.

For some, choosing an RDE2 compliant diesel, while it may be more expensive as it will most likely be a newer model. However, this is only for a first-year payment, so if you’re happy to pay out a larger bulk sum for one year only then diesel may be worth it as after first-year petrol and diesel sit at the same price of £140 for a single 12-month payment.

Servicing costs

Routine maintenance on a diesel car vs a petrol car will be similar prices but bear in mind engine parts and costs. Due to the way diesel engines work, it is more likely to need parts replaced due to the strain the compression in the engine causes on individual engine parts. The relative costs for diesel over petrol do even out more once you reach the high-end cars and SUVs.

Resale value and depreciation

Unless you’re driving a classic sports car, your vehicle depreciation is likely to be one of the biggest expenses you’ll be faced with when it’s time to sell. Diesel cars were generally in high demand, thanks to their fuel economy and encouragement. However after dieselgate, this has all been reversed, and now diesels are depreciating faster as, after 2040, they will no longer be able to be bought brand new. Consumers and the industry are aware of the changes, and so depreciation and resale value are decreasing for diesel, but are levelling out for petrol.


With huge advancements in technology, there is now no difference in petrol vs diesel; it simply depends on driving choice. If you’re driving more on city roads, then the quick responsiveness of a petrol will be much better for you. For those who make long-distance journeys, or who tow a lot, diesel is an obvious choice, as its maximum torque can be produced at lower revs, meaning that the power towing needs can be produced in lower gears and more efficiently.

When choosing between diesel and petrol for performance, keep in mind the environment you will be driving in. For city driving a diesel will not be ideal as the Diesel Particulate Filter (DPF) will clog very easily, and the only way to easily clean it is too take it for a half an hour long trip down the motorway or dual carriageway. With petrol, this isn’t as much of an issue, but for longer journeys, a petrol car will not be as effective.

Road noise

The common perception of the clattering diesel engine, although still prevalent when compared to a petrol engine, is becoming much less of an issue as technology progresses. Now, most people wouldn’t be able to discern a particular difference between a petrol or a diesel car based on volume if it drove by.


The effect your vehicle has on the environment is a hot issue amongst many motorists. Both petrol and diesel produce emissions that have negative effects on our environment, however, diesel cars are more negatively portrayed in the current climate as they produce NOx which contributes to acid rain and can damage people more than CO2. However, both are not good for the environment, hence the government’s decision to ban the sale of petrol and diesel cars by 2040.

Price difference

The price of diesel per litre can be higher than that of petrol in the UK; however, the increased fuel efficiency of a diesel car will mean you have to fill up less making for less of a difference between the two.

If the price is your main concern, then it’s important to consider all the costs associated with each fuel type over the life of the car as opposed to just the current price at the pumps.

So, which is the best?

When comparing diesel and petrol, it is important to remember one thing. One of the key attractions of a diesel powered vehicle is that its engine is generally much more efficient than a petrol run equivalent.

This is why diesel cars are usually slightly more expensive.

Clearly, diesel is more economical in the long run even if it is more expensive per litre. This is slowly changing though. The newest diesel engines are squeezing out more mpg for the same amount of petrol. If petrol cars continue to improve and match the efficiency of their diesel counterparts, then car companies could well find themselves having to think of new reasons why people need to buy diesel.

Do keep in mind regulations and the changing face of the economy, will electric cars soon be taking over and be the preferred choice due to their no tax and low running costs?

Overall, thanks to recent changes in law and the advancements in technology, the choice between petrol and diesel can be judged on driving habits and preference. If you do more city driving, and shorter journeys then a petrol will be better. However, if you’re covering some serious miles and are towing a lot more, then a diesel car will be a better decision for you.


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