Green tyres, fuel savings, CO2 emission - Green tyre: a good idea?

Green tyre: a good idea?

Environment Published the 26/01/2010 by Laurent

The green tyre was invented by the Michelin Group who launched the Energy tyre 17 years ago. Since then, major manufacturers have joined the race for energy savings and have presented several “green” tyre models in their ranges. But are these tyres green in all but name?

Pneu vert : un produit innovant

Let’s start with a definition of what a green tyre is exactly.  When driving, each vehicle is subject to forces that slow its progression: mechanical friction, aerodynamic friction, vehicle inertia, gravity and rolling resistance. It is on this latter point that the green tyre has a role to play in terms of optimizing rolling resistance. The tyre alone can be responsible for almost 20% of a vehicle’s fuel consumption. At each rotation, the materials making up the tyre heat, deform and release part of the energy transmitted by the vehicle: this phenomenon is called rolling resistance and can represent up to one fuel fill in five.

Faced with this fact and strongly encouraged by the European Commission's call at the end of 2007, to reduce emissions of greenhouse gases to 120g of CO2/km by 2012*, manufacturers have continued to look for a low energy-consumption tyre, with low rolling resistance.

European Eco-labelCopyright © :
In 1992, Michelin’s precursor already had its emulators. And in 2001, Goodyear launched its first tyre using patented BioTRED technology, based on corn starch, subsidised by the European Commission and which offered very low rolling resistance. In this field, imagination knows no bounds… However, although this new technology allowed fuel savings, it had the disadvantage of compromising on wear and grip.

For all manufacturers, the challenge was therefore to allow a reduction in consumption without diminishing a tyre’s grip or its longevity. For this reason, scientists investigated the tread, i.e. the part of the tyre in direct contact with the ground. In this field, Michelin managed to replace 95% of the carbon black, which gives the tyre its colour, by silica which consumes far less energy and thus requires much less fuel. This technique gave rise to the Energy Saver tyre, with 20% less rolling resistance and energy savings of 4 g of CO2 / km. This tyre makes up ¾ of Michelin’s sales in Europe. Competitors did not remain inactive: GoodYear launched Efficient Grip and its “Fuel saving” technology, Pirelli the Cinturato P7 and its ENERGY EFFICIENT technology, Bridgestone the Ecopia and Continental its Ecocontact1.

That’s the history, but the question remains: is it a good idea to invest in green tyres? The purchase price is hardly higher than a traditional tyre, but the real question lies in the use this type of tyre can provide. For the same dimension, there are several types of tyres, each with a different usage. Green tyres can be adapted to any type of car: city, saloon, MPV, but to make the most of it, a driver must adopt reasonable and reasoned driving behaviours, both in difficult weather conditions but also during more sporty driving or just in towns. As well as the advantages of fuel savings and a direct impact on your wallet, good wear performance and a good level of grip, you will also be able to add a gesture of “citizenship” and help protect the environment.

Currently, we are in the fourth generation of green tyres. This technology shared by all major manufacturers is available to the consumer, easy to use, effective on performance economical. So the answer is yes, although a green tyre will always be black, its composition and characteristics make it a truly innovative product in terms of energy efficiency and environmental protection.

* This means that petrol and diesel cars will be able to drive 22 and 19.5 km respectively with 1 litre.