Car blogs

What do you think about car tyres?
 
Research suggests not very much, until you need a new set.
 
If I rack my brains I think life, economy, grip, comfort, noise, feel, puncture resistance, price. Add low temperature performance and no tyre can offer all nine. You need a different tyre for snow and ice than you do for summer.
 
But I only come up with nine attributes because I spend half my life answering questions about cars. When people are properly researched, the main factors they think about tyres are economy, safety and longevity.
 
And this is no idle research. It’s straightforward questions the answers to which are verified by a sophisticated cross-questioning “trade off “ technique that makes sure the respondents are revealing what they really think rather than what they think the researcher wants to hear.
 
Longevity remains Michelin’s prime attribute, usually meaning that the company’s slightly more expensive tyres cost less in the long run. Relatively low rolling resistance means they also save you money in fuel. But no driver puts longevity and fuel saving over safety, so Michelin’s tyres must also provide grip at least the equivalent of the competition.
 
And that is what Michelin set out to prove to us at the ADAC testing facility near Berlin.
 
Michelin tyres are tested not by Michelin itself, but wholly independently by DEKRA, based in Narbonne, South West France and by the respected German organisation TUV, that has been testing and certifying products generally for 140 years.
 
The tyres are all bought from different retail outlets in different European markets to prevent any ‘special’ tyres being supplied that could distort the results of the tests.
 
Economy
 
Tyres are responsible for 20% of a car’s fuel consumption (and 30% of a truck’s). Obviously all 20% cannot be eliminated by choice of tyre, but 5% can be. 5% of 50mpg is 2.5mpg. So worth saving.
 
Distortion and flexing increase tyre temperature and increase rolling resistance, so it is vital to run tyres at the correct temperature for the weight of the car and the load being carried. Tyre pressure can increase by 0.3 bar over the course of a morning, so that needs to be taken account of too. As must the compound of the tyre, a mix of carbon black and silica. But since both carbon black and silica are available in different compositions and the compositions of each affect each other differently, getting the right mix and mixing the mix in the optimum manner can make a huge difference to rolling resistance.
 
Rolling resistance that brings the direct benefit of fuel economy can be measured in a drum test by TUV, that conforms to ECE R1007 / SOO 28580 1srt edition 2009.
 
Tyres are rotated against a 3-metre drum driven by an electric motor. The braking effect, deceleration and the power drawn by the electric motor to turn the drum and the tyre are all measured.
 
In these tests of 175/65 R14s with Michelin Energy Saver as the 100% control tyre, the others scored down 81%.
 
Testing 225/40 R18s with the Michelin Pilot Sports as the 100% control tyres the others scored down to 88%.
 
And testing 205/55 R16 winter tyres with Michelin Alpin A4s the control tyre the others scored down to 89%.
 
We also took part in a physical test where three identical Golf diesels fitted with 225/40 R18 tyres were allowed to freewheel off a ramp alongside each other. The tyres were Michelin Pilot Sport 3, Continental Contisport Contact 3 and Bridgestone Potenza REO5A, all purchased by DEKRA in the marketplace rather than supplied by manufacturers. As we saw, the Golf on the Michelins rolled considerably further than the other two.
 
To verify the rolling resistance tests, three other Golfs were taken by DEKRA the same day on a 300 mile convoy run f

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New Michelin tyres last longer, and save fuel without sacrificing grip was originally published by Honestjohn News Feed. Read the full story by clicking here.