DokterBan E-Newsletter

When energy conservation and environmental preservation are addressed in automotive terms, talk naturally revolves around the engine… Yet the tires, sole contact between the car and the road, also play a major role… to the point of becoming “green” themselves!

Saving your tires

Every revolution of a wheel in contact with the ground produces resistance which slows down a vehicle. Repeat this 15 times every second at 100 kph and the friction created causes an increase in engine effort accounting for almost 20% of the vehicle’s fuel consumption. Proper tire maintenance and inflation are the first steps in reducing this phenomenon and the accompanying C02 emissions. It is, in fact, tire pressure which determines the contact area of the tire on the road and the resulting road surface resistance which increases engine work and fuel consumption. By the same token, seemingly harmless things like pinching a tire against a curb can deform the tread and cause uneven contact which can affect fuel consumption.

Reducing rolling resistance

But beyond these simple solutions, the “Green” tires developed by Michelin in 1995 represent a significant step forward. These tires are tubeless, without the weight and fragility of an inner tube which originally caused progressive tire degeneration and increases in fuel consumption. They are of bias-ply (crossed under the tread) or radial-ply (plies at right angles to the sidewall) design and composed of new, hyper-strong rubbers which reduce useless energy dispersion. Instead of the carbon-black usually used, Michelin fabricates its tires from synthetic elastomers having great adhesion characteristics. To reduce the risk of tearing, silica sand is mixed with the compound. In the end this “low rolling resistance” technology produces a 3% reduction in fuel consumption. Good for the environment – and the pocketbook!

Technologies of the future
New generations of tires will contribute even more to fuel economy and respect for the environment. The PAX system, created by Michelin in 1997 should reduce rolling resistance even more. Conceived as the marriage of four interdependent parts (wheel, tire, footprint, and pressure sensor) the system offers less rolling distortion, with better driver input response. The design and shape of the tires increase their efficiency: The front tires have a deeply carved tread, allowing water to be siped away across the entire footprint, and the widened shoulder increases traction while reducing wear. The rear tires have a higher, narrower, profile to contribute to reducing fuel consumption. Finally, the pressure sensor ensures optimal tire pressure all around.

Source:  www.psa-peugeot-citroen.com