Nissan's entry level Almera and Primera models lead the wholelife costs field according to Cowie's figures which take account of the usual criteria plus employers' National Insurance contributions, corporation tax relief and personal taxation. The results reinforce the findings of Highway Vehicle Leasing's Company Car Cost Guide, published last month, in which the Almera and Primera also topped their relative sectors .

Like the Highway guide, the Cowie booklet highlights the huge differences between front-end list price and the total cost of running a company car over the typical three- year/60,000-mile cycle. At 21.27 pence per mile, the Almera 1.4 Equation is the cheapest of the lower medium models produced by a mainstream manufacturer, followed by the Citroen ZX 1.4i Reflex (21.39 ppm) and the Peugeot 306 1.4 XN (21.51 ppm).

In the upper medium sector, the Primera 1.6 Precision tops the table at (24.02 ppm), followed by the Rover 414i (24.24 ppm) and the Ford Mondeo 1.6i Aspen (24.4 ppm). In the supermini sector, the Fiat Cinquecento S (16.61 ppm) and SX (16.97 ppm) are top of the class, followed by the Citroen AX 1.0i Debut (17.61 ppm).

The Renault Safrane 2.0i is the cheapest executive sector car to run at (32.44 ppm), followed by the now discontinued Ford Scorpio 2.0i 8v Executive (32.9 ppm) and the Vauxhall Omega Select 2.0 8v (33.28 ppm).

Defined by engine size, the Volkswagen Polo is the most cost-effective 1.6 litre car at 21.3 ppm, followed by the Ford Escort 1.6i L (22.6 ppm). At 1.8, the Toyota Carina E (24.3 ppm) and the Ford Escort 1.8i LX (24.4 ppm) head the field, while the Hyundai Sonata GLX (25.7 ppm) wins the battle of the 2.0 litre cars.

The guide also identifies the Citroen AX 1.5 diesel as the most frugal car on British roads - returning an average 61 mpg - followed by the Peugeot 106 1.5 diesel at 58 mpg and the Audi A4 turbodiesel at 56 mpg.

The guide is free from Interleasing on 0345 585840.