Michelin adds material saving technology to fuel saving emphasis at Challenge Bibendum

Governments have G8 summits, economists have the World Economic Forum in Davos – for those with an interest in mobility development there's Challenge Bibendum. The 11th Michelin-sponsored forum has grown from an opportunity to present wonderfully creative ideas to the point that the technology on-show at this year's event (held in Berlin for the second time, from 18 – 22 May) are closer than ever to the production technology of tomorrow. True, some of the wackier concepts like free-mind and thought assisted driving that could be seen may still be some way off, and there were a number of prototypes that are more illustration that innovation, but the majority of technology demonstrated at Michelin's window on the roads of future is either 2 – 3 or 5 – 7 years from actually hitting the market.

This is particularly the case when it comes to the latest generation of tyre technology that Michelin exhibited, with vice president technical and scientific communication Pascal Couasnon explaining that mass reducing 10-inch tyres, low rolling resistance “tall and wide” products and self-healing tyres are all something a couple of years away from the market – if indeed the products win over the OEMs. There was even talk of Michelin developing fuel cell technology.

The key message is that in a time of sky high input costs, Michelin is adding raw material saving technology to its product development portfolio in addition to the fuel saving strategy it is well known for. As managing partner Michel Rollier said during the opening ceremony: “Commodities are…scarce and expensive and…likely to become more scarce.”

A showroom for mobility development

According to Rollier, more than 10 years ago when Michelin threw down the first Challenge Bibendum gauntlet, almost no-one was talking was talking about “carbonation” or fuel/emissions control and there was no hybrid or electric vehicle technology on the roads. Now Michelin alone sells 30 million fuel saving tyres a year. And the French-based tyre manufacturer believes the Challenge has helped the development of increased conciousness of fuel efficiency, being – as the company believes – the only global forum that allows all the relevant stakeholders to interact on this issue. For the managing partners (Didier Miraton, and Jean-Dominique Senard were also in attendance), Michelin already represents “the best performance balance” in the market, but the new challenge is “reducing raw material consumption.” In response, the tyre manufacturer has taken to calculating how far cars and trucks fitted with its its tyres can travel per kilo of raw materials. For earthmovers and aircraft the arithmetic is a little different – load per kilo and landings per kilo respectively. 

To quote Berlin Burgermesiter Klaus Wowereit, the event is something of a “showroom for mobility development” and in addition to tyre technology this means that Michelin was confidently promoting the news that it has developed fuel cells as well as being involved in the development of “active wheel” in-rim motor technology that we have heard about before. When it comes to the former the suggestion that Michelin has been doing development work on fuel cell technology was qualified by statements suggesting the company may not manufacturer this technology itself, but it was rather waving a flag to the fact that its research and development engineers have made significant breakthroughs relating to mobility technology outside of the tyre area of specialism for which the firm is known around the world. “We have to be involved in the development of chassis and engine technology,” Didier Miraton explained. When it comes to the active wheel concept Michelin has been pointing to for a number of years now, the latest news is that the firm has achieved the leve of “well developed” technology, with working prototypes demonstrated at Challenge Bibendum. As a result, at this juncture, it appears that the ball is well and truly in in the OEM’s court, however the suggestion is that in-wheel propolusion could conceivably come to market in 5 – 7 years.

Tall and thin, puncture proof and small-wheeled tyres

When it comes to the development of traditional tyre technology, Michelin had plenty to say. First off the company’s engineers maintain that there is still a way to go when it comes to optimising conventional radial tyre technology with fuel economy in mind. Currently the compounds used in Michelin’s tyre construction contain between 50 and 90 per cent sillica, with an average figure for comparable premium tyre manufacturers sitting at around 60-odd per cent. This means the first opportunity to improve the rolling resistance is to improve the make up of rubber used in tyre contruction (see “How low can low rolling resistance tyres go?” for more on this). However reducing the mass of raw materials – particular steel – used in construction while maintain the right balance of flex and rigidity in casing construction will also help. This process is already said to be motoring along at around 5 per cent weight loss per tyre generation. Fuel efficiency can also be improved by virtue of more accurate placement and production control of the component parts. Michelin, for example, manufacturers with tolerances of 10 microns in bead construction.

The second technological “suggestion” Michelin made was the development of a 10-inch diameter wheel aimed at applications such as the Citroen C2. The idea is that by incorporating the kind of rolling resistance tuning described above, coupled with a smaller wheel fitment, the car can save a significant amount of steel and therefore unsprung weight. The problem though with this approach is  would mean bucking the bigger, lower wider trend that has clearly been seen in OE demand over the last 10 years.

Then there is the tall and narrow tyre concept we alluded to before. As you would expect this takes the opposite approach to the small wheeled option that was aimed at city cars. This is because the skinny tyre would be aimed at saloon class autos. The idea is that something like a 195 wide, 19-inch diameter tyre would offer lower rolling resistance and weight than a low and wide alternative. This kind of design is said to be in the hands of an as yet unnamed carmaker for testing. Nevertheless this product is still said to be 2 – 3 years away from the market. 

A possible run-flat replacement

Something else that caught Tyres & Accessories’ attention was the a new type of self-sealing tyre mooted by Michelin. In this case the tyre manufacturer has replaced the traditional inner liner with a  kind of self-healing inner layer. This technology, which is patented by Michelin, is said to be so reliable that the it would negate the need for a fifth tyre, positioning it as an alternative to sidewall support style run-flats which although effective are by design stiffer, heavier and less fuel efficient than conventional tyres. Michelin’s design also potential avoids the pitfalls of some self-sealing tyres already on the market. For example, because the self-healing properties are an integral part of the the inner liner there is no danger that the material could flow to the bottom while the car is parked and cause vibration and unbalance problems that have been observed in some sealant-based alternatives.