THE Christmas holidays will surely see many motorists going on long road trips. To help ensure a fun, memorable and safe journey, French tire maker Michelin recently launched a safety campaign seeking to educate drivers about the importance of proper tire care.
Any driver who has experienced a flat tire will understand that it’s not really the tires that support the weight of a vehicle and its occupants; in reality, it’s the air inside the tires that performs this crucial role. This is the reason Michelin’s Fill Up with Air (FUWA) global safety campaign that is now in the Philippines stresses the importance of proper inflation in road safety.
During the FUWA launch program, Dominique Aimon, Michelin France technical communication director, explained to the media that all endeavors of Michelin revolve around safety. Along with Michael Nunag, Michelin Philippines chief representative, Aimon also explained some common misconceptions about tire care.
Mount new tires at the rear
For various reasons, many motorists end up buying only two tires at a time instead of replacing all four at the same time. Conventional wisdom tells us that since the front tires do most of the work steering the car and driving the car forward (for front-wheel drive vehicles that most of us drive), the new tires should be mounted in front, right? Well, not really, said the experts from Michelin. Aimon said that one dangerous scenario is a loss of traction due to old tires’ advanced wear. If the old tires are mounted in front, their lower level of grip could lead to understeer wherein the car just plows forward even if the front wheels are pointed left or right. If the old tires are mounted at the rear, however, the car could oversteer wherein the rear end of the car swings out during a turn. Understeer is more preferable than oversteer since understeer is more predictable and easier to correct.
Compensate for hot tires
The recommended cold tire pressures for your vehicle is usually printed on the driver’s door, door frame or on the owner’s manual. Michelin.co.uk says that a tire is considered cold when the vehicle has been driven less than 3 kilometers in the past two hours. Each time a tire is driven from rest and travels more than three km, the air inside it heats up, increasing its pressure. And so, inflating a hot tire to the recommended cold tire pressure would not be enough because this pressure will decrease when the tire becomes cold again. Nunag recommends adding 10 percent to the recommended cold tire pressure when inflating a hot tire.
So, if the recommended cold tire pressure for your front tires is 29 psi but the tires are already hot when you inflate them, you must inflate them to 29 psi + 2.9 psi. Rounded off, this gives you 32 psi.
Nunag strongly urges all drivers to purchase a good tire gauge so they can easily measure the cold tire pressure before driving off from home.
Nitrogen is unnecessary
Many automotive establishments are promoting the use of nitrogen for inflating tires, pointing out two main advantages: 1) Nitrogen is inert and, thus, keeps a tire’s pressure more or less constant despite changes in temperature; 2) compared to oxygen, nitrogen has more difficulty leaking through the microscopic spaces in tire rubber, thus nitrogen-filled tires require inflation less frequently.
Aimon, however, discourages drivers from inflating their tires with nitrogen. First of all, he points out that keeping tire pressure constant through changing temperatures isn’t critical for ordinary cars. It’s a different story for race cars and airplanes where filling up with nitrogen is crucial for safety. Furthermore, the Frenchman explained that ambient air is already composed of about 78-percent nitrogen, 21-percent oxygen, and 1-percent miscellaneous gases. As oxygen seeps through the rubber, the concentration of nitrogen inside the tire actually increases over time so drivers using ordinary air to inflate their tires can still get very similar benefits as those who use nitrogen. Aimon also notes that drivers who use nitrogen are more likely to neglect checking their tires, thinking they do not need to check their tires’ pressure at all.
Use a permanent repair patch
There are two common methods of repairing tire punctures in the Philippines: the use of a patch that is attached to the inside of the tire and the use of a rubber plug that is inserted into the damaged area using a giant needle. The latter is done without dismounting the tire from the wheel. Neither of these is recommended by Michelin.
Nunag said the problem with using a patch on the inside of the tire is that it doesn’t keep water and moisture from entering the tread from the outside, which, in turn, could cause the steel belts to corrode. On the other hand, a plug is a temporary fix and since this can be done without dismounting the tire, inspecting the inside of the tire for damage is often overlooked.
Michelin recommends the use of a mushroom-shaped permanent repair patch that performs the job of both a patch and plug—only better. Nunag says tire technicians at Michelin outlets will first “clean” the puncture to make sure that no steel belts are exposed. The inside of the tire underneath the puncture is then scraped to make the adhesive cement adhere more strongly. The stem of the PRP is then inserted through the puncture, sealing the puncture from the outside, while the head of the PRP seals the puncture from the inside of the tire.
Replace tires five years after purchase, not five years after it was manufactured. Many car manufacturers and safety experts recommend discarding a tire five years after the tire is manufactured, even if the tread are still in good condition (the week and year when the tire manufactured is stamped onto the tire itself). Michelin, however, is so confident about the durability and longevity of its tires that it may not be necessary to discard a Michelin tire just because it has turned five years old. Nunag said Michelin dealers are trained to store new tires away from heat, sunlight and solvents exposure to which shorten the life span of tires.
And for as long as the tread and the rest of the tire have not been subject to damage or excessive wear and tear, a Michelin tire can see continuous service way beyond its fifth year. Nunag does recommend bringing tires to a Michelin dealer for annual safety inspections once the tires turn five years old.
Image credits: Eric Ayrton S. Soriano