Petrol or diesel?
May 2020

Petrol or Diesel Which Car To Buy?

If you’re looking to buy a vehicle and are overwhelmed by the choices on offer, there’s one more thing to consider: petrol or diesel? Both have advantages and disadvantages, and both are continually making strides in the manufacturing of new vehicles.

Diesel driven cars are not the noisy, smoky vehicles they used to be ten years ago. Advances in engineering technology have made it such that they compare favourably against petrol-driven cars both in performance and refinement. All the while the gap between petrol and diesel is closing. Manufacturers are working to improve torque for petrol engines on the one hand and responsiveness for diesel engines on the other.

Here, we look at the pros and cons of both types of fuel. As with any purchase you make it comes down to you as an individual and your priorities. What do you want most from your vehicle?  Consider the running costs as well as driving preference, and then assess the comparisons below to help you make up your mind.

Petrol Powered Vehicles – Pros & Cons


  1. Cars are less expensive to buy.
  2. Maintenance costs are lower.
  3. Tend to weigh less than the diesel equivalent - an important consideration for high performance.
  4. New-generation petrol engines are becoming smaller, lighter and more efficient with little performance loss.
  5. The price difference between petrol and diesel is narrowing - petrol will soon become cheaper to buy.

 Best if you’re using your car mainly for city driving.


  1. Less fuel-efficient at 27%compared to 35% for diesel.
  2. Higher depreciation rate than diesel cars.
  3. Emits more carbon dioxide, carbon monoxide, and hydrocarbons.
  4. Lower torque in small petrol cars is more vulnerable on highways.
  5. Overtaking requires more frequent gear-changing.

Modern Diesel-Powered Vehicles


  1. Smoother than 2- and 3-cylinder petrol engines.
  2. Gets good mileage and delivers better fuel economy at 15 – 20% less fuel consumption than petrol.
  3. No need for ignition tune-ups since they do not have spark plugs or distributors.
  4. Engines are more solidly built to withstand the higher compression and therefore last longer.
  5. Able to produce higher torque or ‘pull’ at low speeds allowing them to overtake easily.
  6. Delivers good fuel economy even when towing.
  7. Diesel engines do not use spark plugs or distributors and therefore have no need for ignition tune-ups.


  1. Tend to be more expensive to buy.
  2. Diesel fuel costs typically more than petrol.
  3. Servicing and repairs tend to cost more than petrol.
  4. While routine maintenance costs are similar for petrol and diesel, serious problems such as a clogged particulate filter in a diesel engine can mean an expensive replacement. (Tip: This happens if you use your diesel vehicle mainly for city driving. Taking the car out for a drive on the motorway regularly enough will help clear the filters.)
  5. The more advanced technology makes it more expensive to repair. (Tip: Keep it well maintained regularly.)
  6. Produces more nitrogen particles, sulphur dioxide, and black smoke particles. Despite lower CO2 emissions diesel particles are linked to breathing disorders.

In Summary

In summary, if you intend putting in a lot of driving especially on the open roads and long journeys, diesel is a good choice. But if use your car mostly for short distances and city driving, a petrol-driven city car would make better sense.

Bear in mind that the diesel particulate filter (DPF) in modern diesel vehicles can clog if you don’t drive it regularly on the open road. This filter is an important component as it helps combat pollution, but a clogged filter is a costly expense. If your travel is mainly local, diesel may not be a good choice.

Disclaimer: This information is for educational, or entertainment purposes only. It must not be construed as advice, legal, financial, or otherwise. We do not make any warranties about the completeness, reliability, and accuracy of this information. The views and opinions are those of the author and not necessarily those of Auto Pedigree.