If you thought that tyres are presented fait accompli to car manufacturers on a 'stick these on your car' basis, think again.

These days the black rubber bits that keep your motoring show on the road are built with the tyre people very much working hand-in-glove with the carmakers.

There's a thing called 'homologation', where the tyre manufacturer has his product assessed as recommended original equipment in terms of a new car coming up, or for a car in existing production.

It is a labour-costly process, as well as being high-tech. It takes usually 15 people a full year to approve a tyre specification for a car, and in the process they will test the tyres over a distance of 12,500 km. Some 1,200 km of this is dedicated to validate handling and braking characteristics on dry surfaces, and 500 km on wet surfaces. A further 500 km of testing will work out the noise and other factors of a particular design.

Michelin is one of the most respected manufacturers of car tyres, and in its testing programme each year a total of 2.5 million tyre-km are driven, involving some 500,000 working hours and a total of 6,000 tests.

It is work that does pay off. Michelin is awarded around 200 homologations a year from various manufacturers. Since the J D Power customer satisfaction surveys crossed the Atlantic (to the UK in 1998 and Germany in 2001), the tyre brand has achieved the best customer satisfaction reports in the UK for five years in succession, and in Germany for both of the surveys so far.

And across its markets, 80 per cent of of car-owners in the top-of-the-range segment buy Michelin when they change their tyres for the first time. Overall, studies in 2002 have indicated that customer loyalty in the replacement tyre market has increased to 66 per cent for Michelin, far ahead of the loyalty rating for its closest competitor.

As brand image goes, Michelin in Ireland is premium, as it is in the US. "In fact, in an automotive brand awareness study in the US, Mercedes-Benz came first and Michelin second," Michelin boss for Europe Scott Clarke told me recently.

That image is reinforced by a look at the names of the carmaker 'partners' with whom the Michelin company works - Mercedes-Benz, BMW, Renault in Formula 1, Porsche, Audi in endurance racing such as Le Mans, and Peugeot-Citroen in the World Rally Championships.

And last year, Michelin tyres were approved for new vehicles Mercedes AMG SL 55, BMW M3 CSL, Audi A8, Audi RS6, Maybach, Porsche Cayenne, Porsche 996, Renault Megane, Renault Vel Satis, Peugeot 807, VW Passat, Ford Mondeo and many more.

Across Europe, one vehicle in three was equipped with Michelin tyres in 2002. In sport and supersport segments, Michelin's Pilot Sport range accounts for nearly half of sales volume, particularly with Porsche, Mercedes AMG, BMW Motorsport and Audi quattro.

To get this kind of penetration, Michelin sends out technical teams to work with the manufacturers at a very early stage of a new car project. Tyres and chassis characteristics are very interlinked, and the new generations of the two key road tyre ranges - Energy and Pilot Sport - have been developed particularly by cooperation with Renault and Porsche respectively.

The target models for the latest generation Energy tyre range through Renault's Clio and the Peugeot 206, VW's upcoming new Golf and the Renault Megane II, Ford's Mondeo and a number of MPVs. The so-called 'Touring' segment in a new classification of tyres.

This segment represents almost 80 per cent of the total original equipment market in new cars, and some 62 per cent of the replacement tyres market.

As performance increases, cars get bigger wheels, and there's been a major growth in 15" and 16" wheels - and consequently their equivalent tyre sizes - since 1997. In fact, the latter size has experienced growth of almost 400 per cent in that time.

Last year, Michelin sold 26 million of its previous generation Energy tyres in Europe, and overall around 8 per cent of all cars on the roads of Europe are fitted with Michelins. That's around 64 million tyres.

Count them yourself if you want ...