What Car? Q&A - Should I buy petrol or diesel BMW?

Q: I have decided that my next car will be a two-year-old BMW 5 Series Touring automatic. My dilemma is whether to buy the 525i or 525d (or possibly 530d).

My mileage currently is no more than 8000 miles per year, and will be financed personally i.e. not a company car. I tend to keep my cars at least five years.

The factors seem to be that the diesel is more ecomnomical, but that that diesel fuel costs more. The 525i Touring as a used car is cheaper than the equivalent 525d. The 525d may have better residuals, but in five years time I would not get the difference in cost back at trade-in.

In What Car? you seem to recommend the 525i as a saloon and 525d for the estate. I currently have a 525i saloon (2000 model) and think the engine is superb and reasonably economical. I have never owned a diesel car.

Martin Peckham

A: You're right that the diesel version would cost more to buy and run than the petrol. You're not doing enough miles to pay back the price premium on the car, but you may end up more or less even thanks to stronger resale values.

However, the 525d is still the one we'd recommend. Why?

We feel the 525d provides plenty of low-down muscle that suits powering this car - especially if it is heavily laden or being used as a tow car. That's what we feel you have to consider whether you opt for petrol or diesel. It's not the economy of the diesel that makes it a winner here, but its pulling characteristics.

There's no doubt, however, that the diesel is less refined than the petrol - you will hear it grumble if you push it hard. If you have never owned a diesel car before, take it for as long a test drive as possible, in town and on the open road, to see if you think you can live with the extra noise.