Here is the ongoing debate about whether it is really worth switching from petrol top to diesel, despite the widening gap in the price between the two fuels.

Dave Brooks is 59 and drives a Y-reg Citroë*Xantia petrol hatchback which returns 30mpg. He wants something more economical. He reckons that he would need a vehicle that would do 50mpg to make the switch to diesel worthwhile. Dave's 13-year-old son is a triathlete. Budget: £4,000.

Glass's Guide, who produce used vehicle price information, have recently calculated that it takes seven years to pay for the difference in a diesel over a petrol vehicle. Certainly in Dave's case, with £4,000 to spend, I would like to think that, whatever his annual total mileage is, he should get the slightly smaller premium he would have paid for diesel covered rather quicker than that. Cheaper diesels will usually have higher mileages and may need more urgent repairs than a cheaper petrol equivalent. Dave will be racking up some reasonable mileages providing support for his son's athletic activities. In that case he will see a benefit, and filling up less overall despite the cost of diesel should prove worthwhile. When lugging equipment around, the pulling power of a diesel is more suited to this kind of use.

A car for the head

Dave suggested some small estates to me. The old model Vauxhall Astra is surprisingly spacious, yet compact, and is around in quite large numbers with several diesel engines. A 1.7 DTi will manage up to 57mpg as an average. There are loads about and many have led tough lives as company vehicles, but the nicer ones with about 50,000 miles can be found at around £3,500. An alternative could be a Toyota Corolla estate with a 2.0 diesel engine which is very rare indeed, quite boring but should return 47mpg with the added benefit of being utterly reliable. Inside it is not that versatile or large. So, on second thoughts, the next practical model up from the Astra would be worth considering, such as the people-carrying Zafira.

A car for the heart

I suggest Dave consider a Citroë*Xantia estate diesel. I found a 1999 example which has covered a little more than 50,000 miles, with the very frugal 2.0 HDi engine that should return at least 50mpg overall. This was a very well-equipped SX version with air conditioning, as well as a sat-nav system. All this for £3,495. There are other Citroëns, of course, and perhaps the compact people carrier in the shape of the Xsara Picasso would make some sense. I found a 2003 2.0 HDi SX which again should return 50mpg; a 60,000-mile example could be found at a dealer for £2,975.

Please write to Car Choice, Features, Independent House, 191 Marsh Wall, London E14 9RS, or email James Ruppert at, giving your age, address and phone number, details of the type of vehicle in which you are interested and your budget.

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