Used car buyers guide: Petrol vs Diesel

Used car buyers guide: Diesel Cars vs. Petrol Cars

When it comes to choosing a used car, one of the fundamental decisions you'll need to make is whether to opt for a diesel or petrol engine. Both have their unique advantages and characteristics, including running and car servicing costs appealing to different types of drivers. In this blog post, we will delve into a comprehensive comparison of diesel cars and petrol cars to help you make an informed decision for your next used car.

Fuel Efficiency and Cost

Diesel cars are known for their superior fuel efficiency compared to petrol cars. Diesel has a higher energy content per liter than petrol, resulting in a better return when it comes to MPG. This advantage often translates into lower fuel costs over the long run.

On the flip side, while petrol cars generally have a lower fuel efficiency compared to diesel, the cost of petrol is often lower than diesel. This can offset the efficiency advantage of diesel to some extent, especially for those who primarily drive in urban areas or have lower mileage requirements.

For individuals who cover long distances regularly, such as commuters or frequent travelers, a diesel car might be the more cost-effective choice. However, if you're more likely to be making shorter journeys then we would recommend a petrol powered vehicle.

Performance and Power

Petrol engines are renowned for their responsive and smooth performance. They typically have a broader power band, allowing for quicker acceleration and a more enjoyable driving experience. This makes petrol cars ideal for those who seek a sporty and dynamic driving style.

Diesel engines, on the other hand, are known for their torque. While diesel cars may lack the higher-end power of petrol cars, they compensate with robust low-end performance, making them suitable for practical applications like pulling trailers.

Environmental Impact

In recent years, environmental concerns have played a significant role in shaping preferences for car buyers. Diesel engines, historically known for higher emissions of pollutants like nitrogen oxides (NOx) and particulate matter, have faced scrutiny for their environmental impact. Many regions have tightened emission standards, making it challenging for diesel engines to meet them without additional technologies like selective catalytic reduction (SCR) systems.

Petrol engines, while producing fewer NOx emissions compared to diesel, still emit carbon dioxide (CO2) and other greenhouse gases. The good news for the environmentally conscious motorist is that modern day vehicles are far less pollutive than their predecessors. With some studies even showing that modern vehicles are able to clean air in areas with higher pollution levels! 

It is also important to remember that emissions testing is an important part of of the MOT test procedure and your vehicle must meet the set standards to pass each year.  

Maintenance and Longevity

Diesel engines are renowned for their durability and longevity. The robust construction and lower RPM operation often result in less wear and tear, leading to a longer engine life. Additionally, diesel engines generally require less maintenance due to their design and the fact that they don't have spark plugs or ignition systems.

It is not uncommon for us to see high mileage diesel motors happily carrying on past the 150,000 mile mark and beyond.

Petrol engines, while still durable and long-lasting, may require more frequent maintenance due to their higher-revving nature. This can include spark plug replacements and other components related to the ignition system.

The main thing to understand here is that whether its petrol or diesel powered, your car will last much longer when you service and maintain it properly.

Vehicle Availability 

When it comes to availability this really depends on the class of vehicle you are looking at. Most bigger, heavier cars tend to be diesel powered while smaller city cars tend to be petrol powered. For example if you're looking for a diesel powered Ford Fiesta (yes they exist!) there will be far less choice than if you were looking for a diesel BMW 5 series. As an indication of which is more popular, there are currently 150,000 Diesel cars on Autotrader with 250,000 petrol cars for sale. 


Ultimately, choosing a between petrol powered and diesel motors comes down to your specific usage needs for your next used car. 

If you're going to be doing a lot of long distance travelling or pulling a trailer then a diesel car is probably the car for you. If its city driving and the occasional longer journey then a petrol powered car is what you need. Of course there are other factors to take into account here but as a general rule that's the advice we would give. 

About us

E&J Jarvis ltd have been servicing cars in Southampton for over 75 years! we are a fully equip MOT test centre and car service station offering high quality repairs without the dealer price tag.  If you're looking for your next car or would like to service or repair your current one, our team will be happy to help.

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