Should I buy a diesel or petrol car?

Many people have trouble choosing between petrol and diesel care, Which has a lot of information, find out more here. Some factors include:

Petrol and diesel fuel prices – In the UK, diesel can be more expensive than petrol. With fuel pricing favouring petrol, and advances in petrol engine technology, making their efficiency ever closer to that of a diesel, there must be question marks over the diesel price premium – typically £1000 to £2000 more, for models of the same specification.

Residual values of petrol and diesel cars – Diesel cars generally retain their value better than petrol versions. They’re currently in high demand, thanks to people looking for cars with better fuel economy and lower car tax rates. However, the Which survey shows, on the whole, that diesel-powered cars are still slightly less reliable than petrol ones. And while routine maintenance costs are similar for petrol and diesel, it is potentially more expensive to repair a diesel if anything serious goes wrong. In particular, diesel engines use particulate filters, which can get clogged (especially if only used for short journeys), and the cost of replacement can stretch into thousands of pounds.

Other factors include

  • Conventional wisdom says that petrol models tend to be faster, smoother and quieter than their diesel counterparts. However, diesel cars have become more refined, as carmakers have developed ways to mask the trademark signs – to the point where you may even struggle to tell the difference in some upmarket models. Often, the visible give away is the rev counter, which will have a much lower rev limit than one for a petrol car.
  • Diesel engines also offer increased torque (pulling power) from low revs, which is especially useful when towing or overtaking.
  • Diesel cars are more efficient, and so use less fuel for a given mileage, potentially causing less damage to the environment (especially if fitted with a diesel particulate filter to trap the nasty soot-like emissions many associate with diesels).

Is pollution worse from diesel or petrol?

Over half of new cars are now diesel, compared to just 14% in 2000 driven in part by the fact we thought the increased fuel efficiency would be better for the climate.

It is harder to control pollution from diesels than from petrol, and for this reason, European standards for diesel exhaust have not been as strict as those from petrol cars. Access to low emission zones in Germany reflect the difference in pollution emissions with open access being permitted for petrol cars made after 1993 but only for the most modern diesels. It is also becoming clear that the technologies to control some types of pollution from diesels are not effective during real-world driving.

The air pollution penalty from diesel cars is often justified in terms of the saving in CO2 emissions compared with petrol. However, new analysis is calling this orthodox view into question. If climate warming emissions of black soot are considered along with the difficulties of producing sufficient diesel to meet demand, then the climate change benefits from diesel largely disappear and maybe Governments will look to change this trend to diesel engines – we’ll keep you posted!