Petrol vs Diesel – Which is best for you?

In the ever-evolving world of vehicle technology, choosing your next car involves understanding many drivetrain options. While electric vehicles are gaining momentum, the advancements in petrol and diesel technologies shouldn’t be overlooked. 

These traditional powertrains are not just holding their ground but evolving with improved efficiency, extended range, and lower emissions.

Following our comprehensive guide on the pros and cons of Electric vs Hybrid, we now focus on the differences between petrol and diesel vehicles. Your vehicle choice will depend on driving habits, environmental considerations, individual preferences, and budget. 

Keep reading to make sure you’re fully informed on all your options.

What are the differences between Petrol and Diesel engines?

Diesel engines generally have better fuel efficiency and torque, making them more suitable as heavy-duty vehicles and for specific jobs like towing. In contrast, petrol engines often offer smoother performance and are more common in smaller vehicles. 

Petrol engines ignite a mixture of air and vaporised fuel with a spark plug, while diesel engines compress air and finely spray diesel fuel until it spontaneously ignites.

Petrol vs Diesel – The Pros and Cons

Here we have weighed up the basic differences between petrol and diesel cars, as well as the pros and cons for both, to help you understand the differences:

Diesel Cars

Pros

• Fantastic efficiency
• Low CO2 emissions
• Powerful driving experience
• Long-term savings for high mileage drivers
• May have cheaper road tax than a diesel equivalent

Cons

• Older models produce other emissions such as NOx
• Can be more expensive to purchase
• Noisier than petrol engines
• Diesel particulate filters can get blocked if not used for frequent longer journeys (the heat buildup during long journeys clears this).

Petrol Cars

Pros

• Cheaper to buy
• Lower servicing costs
• Cheaper insurance

Cons

• Lower efficiency

• Less Torque available for towing

Petrol vs Diesel Car Pricing

Historically, diesel cars come with a higher initial price than their petrol versions, with much of the cost attributed to the robust engineering required for diesel engines. 

However, as manufacturers invest in cleaner and more efficient petrol engines and with advancements in petrol engine technology and the stringency of emission regulations, the upfront cost gap between diesel and petrol vehicles is closer than ever, making the choice even more tricky!

Maintenance Costs

Every car owner wants a reliable and affordable car, but how do the maintenance costs stack up between petrol and diesel vehicles? 

Road Tax

Road tax prices are worked out in bands based on the C02 emissions of the vehicle. So, as a diesel engine is more fuel efficient than its petrol counterpart, the tax may fall into a lower band than the petrol version of the same model.

Insurance

Insurance providers factor in how much a car will cost to repair, including replacement parts. Modern diesel cars use expensive filters and emission control systems, which means they can be more costly to repair than petrol models, which means generally, petrol models are cheaper to insure.

Emissions Charges

Euro 6 is the latest emission standard the European Union sets for vehicles, including petrol and diesel cars. It imposes stringent limits on the number of pollutants that vehicles can emit, such as nitrogen oxides (NOx). Compliance with Euro 6 standards signifies that a car meets the latest and more environmentally friendly air quality and emissions criteria. Euro 6 came into force in September 2015, so all vehicles registered after this date will generally be Euro 6 compliant. Some manufacturers incorporated the Euro 6 compliance well before the 2015 deadline, so if you have an older model, you may still find it complies.

Some older vehicles may incur emission charges when driven in certain cities such as London. The Ultra Low Emission Zone (ULEZ). The ULEZ standards depend on the category of vehicle being driven:

Euro 3 for motorcycles, mopeds, motorised tricycles, and quadricycles (L category)

Euro 4 (NOx) for petrol cars, vans, minibuses, and other specialist vehicles

Euro 6 (NOx and PM) for diesel cars, vans, minibuses, and other specialist vehicles

You can check online using the registration number before buying a diesel or petrol model to see if that vehicle meets ULEZ requirements.

Resale Value

The resale value of vehicles depends on several factors and is often greatly determined by overall used car market conditions and current consumer trends. Factors such as whether the vehicle is ULEZ complaint, mileage, past servicing history and current demand will contribute to the car’s value. 

Fuel Consumption

Generally, diesel fuel tends to have a higher energy density, providing more mileage per litre than petrol. This means that they cost less to run than petrol cars over longer distances. You should consider a diesel if you cover over 12000 miles a year. 

Petrol Cars:

• Petrol engines are generally more fuel efficient at lower speeds and in city driving conditions.
• Petrol engines are known for their smoother and quieter operation.

• Petrol cars are often preferred for short-distance commuting and urban driving.

Diesel Cars:

• Diesel engines are more fuel-efficient at higher speeds and are well-suited for motorway use.
• Diesel engines provide more torque at lower RPMs, making them efficient for towing and carrying heavy loads.
• Diesel cars are often chosen for long-distance travel

Environmental Considerations

You might be questioning if there are significant environmental differences between petrol and diesel fuel. Petrol cars typically emit lower NOx and particulate matter levels than their diesel counterparts, historically making them more environmentally friendly regarding air quality. However, diesel engine technology is constantly evolving to address environmental concerns, and many modern diesel engines now feature particulate filters and improved combustion techniques to reduce emissions significantly. 

Petrol vs Diesel Performance

Torque and Horsepower:

Petrol engines are typically known for their higher RPM range and are more suitable for linear acceleration and responsive driving at higher speeds.

Diesel engines excel in torque production, which makes them better suited for lower RPM ranges. This results in low-end power, which is suitable for towing and driving at lower speeds. 

Acceleration:

Petrol engines generally provide smoother acceleration, which is ideal for drivers wanting a more dynamic and sporty driving experience.

Diesel engines offer robust low-end torque, resulting in powerful acceleration at lower speeds, but are less responsive during high-speed acceleration than petrol engines.

Experience:

Petrol vehicles are often chosen for their performance, making them suitable for urban commuting and responsive driving. They are popular because of the smoother and more refined driving experience. In contrast, diesel vehicles provide better fuel efficiency in specific scenarios, making them a preferred choice for drivers wanting better fuel economy over high-speed performance. 

Misconceptions about Diesel Engines

Diesel cars are the most significant cause of air pollution. Cars only make up 14% of the UK’s NOx emissions, and in London, where road transport is responsible for half of the NOx emissions, diesel cars only produce 11% of this.

Diesel car emission performance stats aren’t achievable. All new cars, including diesel, must meet the Euro 6 emissions standards; for diesel cars, the permitted level of NOx dropped from 180mg/km to just 80mg/km. 

The Government is clamping down on diesel. Only older diesel models with high emissions are likely to be impacted by new legislation.

The Future of Petrol and Diesel

Combustion engine cars are getting cleaner to meet the ever-changing legislation. However, the UK government has announced a ground-breaking ban on the sale of new combustion engine vehicles, including petrol and diesel cars and vans, from 2035 as part of their ambitious plan to achieve net-zero carbon emissions by 2050. 

This move reflects a significant shift toward sustainable transportation and a commitment to addressing climate change by promoting the adoption of electric and other low-emission vehicles. However, the ban does not impact used cars, which means they are a viable option and will be for years to come. 

What is better, petrol or diesel? 

Consider how you use your car to make an informed decision: 

• How many miles do you drive a year? 
• What type of roads do you drive on? 
• Will you use the vehicle for towing? 
• How many years do you intend to run the vehicle? 
• What size of car do you need? 

Our exploration of petrol and diesel vehicles aims to provide you with the knowledge to select a car that suits your driving style, preferences, and requirements. With a wide selection of both petrol and diesel cars, you are sure to find your perfect car. We also have a range of hybrid and electric vehicles available.

Book a test drive with us today; our experts at T W White and Sons are always on hand should you require further advice, so don’t hesitate to get in touch.