Can we have some Primacy, please?

Michelin's new low-rolling resistance tyres put to the test.

The Sriperumbudur track can get very hot during the day. So hot that track temperatures are known to exceed 50 degrees centigrade without the sun venting its anger. Perfect conditions, then, for a company like Michelin to test their new range of tyres — the Primacy LC.

The Primacy LC is a new range of tyres, developed by Michelin specifically for the Asian market. Available in 15 and 16-inch sizes, they are aimed at cars such as the Skoda Octavia and Laura, Honda Accord and Civic, Toyota Camry, Innova and Corolla among others. It’s positioned as a performance tyre, keeping the environment and fuel efficiency in mind. Now that’s a very difficult trade-off to achieve, since performance generally means lots of grip, but with not so good fuel efficiency. Michelin, however, have managed to achieve that with the use of silica. With 98 per cent silica construction, the tyres not only run cooler, their life is also significantly enhanced. The LC is a low rolling resistance tyre, with relatively lesser friction between the road and the tyres.

To get an idea, we tried out a battery of tests comparing Brand X with Michelin’s Primacy LC. In the low rolling resistance tests with Skoda Octavias, we found that the Primacy LC equipped car would roll to a stop much farther than Brand X when being rolled to a halt at identical speeds. A lower rolling resistance essentially means the tyres will encounter lesser friction and therefore the car will encounter lesser resistance in putting its power down. Effectively, that results in better efficiency and lower emissions.

But low rolling also traditionally presents other problems, like a lack of grip. Michelin claim to have found a solution by making the tyre seven per cent narrower, yet 13 per cent taller than the tyre it replaces — the MXV8. With such a construction, Michelin says it increases rubber contact on the road by as much as 21 per cent. To put that claim to the test, we tried two things — a wet braking test and a wet handling test. In the wet braking test, the car was brought to a halt on a wet patch of road from 60 kph to zero in a straight line, to study the effects of construction and pattern design. The Michelin tended to brake straighter and tighter in comparison to Brand X, stopping short some three metres on an average.

In the wet handling test, the car was put through a slalom and a fast corner to check the effects of directional change and lateral grip. After a couple of cones, a Brand X equipped Corolla would struggle to find grip, while the Michelin tyres held their line better and even created lesser understeer as they moved between the cones and powered out of the corner.

While grip and rolling resistance are one part of the story, road noise is altogether different. Traditionally, road noise is caused by car design and tyre construction techniques. One way of eliminating tyre noise is to construct it in a way in which it behaves a like ribbed tyre. Michelin have cleverly incorporated this factor into their tyres and to demonstrate the efficacy, they brought in experimental block, ribbed and Primacy LC tyres for the test. As usual, block tyres created a heavy humming sound, while the ribbed tyres were as silent as a whisper. The Primacy LC married the best of both and were near ribbed tyres in terms of road noise.

All of these features have helped the Primacy go one up over its predecessor as well as match or better the characteristics of its competitors, with near competition-like pricing. Michelin also claim that the cost of a new tyre can be written off by the savings of using a set of four Primacy LCs with less than 45,000 kilometres of use. With pretty good performance characteristics and economics in play, that does sound like a ‘hot’ proposition.