Cold tires are the foe of the racing driver, so it's no surprise that teams go to great lengths to heat up the rubber to give the tires grip as soon as they touch the asphalt.
The system that Team McLaren Mercedes has for doing this is straightforward. A control box allows the tire technician to set the temperature. Power then flows along the wires to the blankets, which are wrapped around the tires. Elements in the blankets are surrounded by a conductive gel, which heats the surface of the rubber to in excess of 100 degrees C.
"Basically, we wrap up the Michelin tires in the blankets, stack them up, plug them in and they're subjected to a constant heat until we turn them off," says Marcus Prosser, Race Team Tire Technician. All clear-cut, you think. But just consider that each tire needs to be heated for a minimum of two hours, and that numerous kinds of tire must be heated and on hand. Now it is getting a little more complicated.
"We have all three options of Michelin tires warming: dry, intermediate and full-wet tires," Prosser continues. "We also heat the different scrubbed tires that have been used over the weekend, as putting a new tire on is not always the best course of action. We even had full wets warming in Bahrain , where the track is in the desert and it hadn't rained for five months! We have to be prepared."
The warmer the tire, the more grip the driver has. Watch a re-start after the Safety Car has pulled into the pits and you'll see that for yourself.
Rubber temperature also influences the pressure of the tire. "Pressure is as important as grip," explains Prosser. "If the pressures are low, the car will sit lower down. That makes a softer ride, whereas higher pressures make a stiffer ride. The race engineers will often request a pressure adjustment along with a mechanical change."
With so much importance placed on tire temperature, it is no surprise that Prosser and the team constantly monitor the control box to make sure everything is going to plan.
* Technical Spec
* Length – 200m of filament per warmer
* Temperature – In excess of 100 degrees C
* Number of sets – 24 in 2005
Source: McLaren Mercedes