A brand new car will lose an average of £21.40 per day, £3,966 in total, during the first six months of ownership according to new research.

Analysis by Used Car Buyer magazine of popular models highlighted the £9.6bn loss in value suffered by buying a new car. Industry forecasters expect 2.4m new cars to be registered during 2004.

Even with the discounts widely available on new cars taken into account, the findings confirm that depreciation is the single biggest cost in running a car – the equivalent of 66 pence per mile (over 6,000 miles) on average or a 28.6% hit on the original investment in the first 182 days.

Owners of luxury models like the Mercedes S-class or Audi A8 feel the biggest losses, where depreciation runs at £108 per day during the first six months.

"It's not difficult to see why nearly a million people opt to buy a manufacturer approved used car in the 6-24 months old bracket every year," says report author and price guide expert, James Ruppert of Used Car Buyer.

"Letting new car buyers take the initial financial sting out of owning is a no-brainer. Even then, consumers still have to choose the right models to take full advantage of depreciation, or protect themselves against its effects."

Slowest Depreciators