Findings from the latest RAC Cost of Motoring Index reveals the cost of running the average new car has grown to nearly £5,000 a year, or £14 a day.

But the bad news for automotive businesses is that maintenance costs fell 7% from £292 to £271 and average finance costs fell by 4% from £990 to £948.

The index, which tracks all costs associated with owning and running 17 different models of car also reveals that rising fuel prices have increased the yearly fuel bill to £1,154, or £22.20 a week, an increase of 11% in six months.

But according to RAC technical director David Bizley, the largest cost factor in all new cars remains depreciation, with the average car owner losing £1,987 a year, or more than £38 a week as values slide.

The cars profiled are intended to represent a broad cross-section of the British parc. At the most frugal end of the spectrum is a 1.0-litre Toyota Yaris which, according to the index, costs £8.73 a day to run. Compare this with a Porsche Cayennne turbo which will set owners back £52.40 a day.

The figures for fuel, maintenance and insurance costs are based on the assumption that each car does 12,000 miles a year which is a standard used by the insurance industry to calculate premiums.