The internet can be a great business tool. No need for a desk strewn with brochures, price lists and spec sheets, just instant access to the information you need. At least, that's the theory.

When done properly, a website can be a great time-saver. But done badly it's a frustrating tangle of clicks, slow downloads and style without substance.

We've surveyed the websites of the 20 biggest-selling fleet carmakers to find which really deliver.

Firstly, we've checked the Google ranking of each site by typing in the manufacturer's name and the word 'fleet'. The higher up the results list the fleet home page appeared, the higher the score. Secondly, each site was assessed for ease of use. Could basic information like prices and emissions data be tracked down quickly without endless clicking from page to page? And how easily could the fleet section be found from the main home page?

Points were on offer for attractive design, and we've assessed the quality of the downloadable brochures and spec sheets. If a manufacturer goes the extra mile with P11D price lists for each model, so much the better. The presence of a basic tax calculator gets some credit, too, although the more sophisticated it is, the higher the score.

There is a limit, however, to what even the most comprehensive website can convey, so a prompt response to email inquiries and a prominent phone number (preferably for fleet sales specialists rather than general customer services) earns more credit.

Finally, the quality of the dealer finder and other useful features further boosts the scores, which we've totted up to give an overall percentage.

Audi 76%

One of the front runners in '07, Audi has slipped a bit. The biggest no-no is the absence of a tax calculator, which Audi says is temporary while a new one is developed. Otherwise this remains an understated and stylish site, with some useful extras.

www.audi.co.uk/fleet

BMW 88%

This is almost exactly how it should be done. Everything you need is just a click or two away from the home page. The tax calculator is as clever as they come, and the find-a-dealer service will even give you driving directions. A few more extras would keep business users coming back for more, but we're quibbling.

www.bmw.co.uk/corporatesales

Citroen 72%

Citroen has given its website a lick of paint and it shows. Not only does it rest more easily on the eye, the tax calculator has been improved, and now gives tax figures from a company perspective as well as BIK. It's a shame we're still waiting for a response to our email.