Once and for all: NEVER inflate your tires to their maximum air pressure!

Dear Car Talk

Dear Car Talk | Jan 01, 1996

Dear Tom and Ray:

I was recently told by my local tire store manager, while fixing a leaky valve stem, that I should be inflating my tires to the pressure listed on the tire, not the pressure listed on the door or owners manual. In the case of my Taurus, he inflated them to 41 psi. This seems excessive. What is the answer? The pressure on the tire or the pressure recommended by the manufacturer?

RAY: The TIRE STORE manager told you that? The MANAGER?? Holy crow bar! There's a guy with his headlight firmly emplanted in his taillight socket!

TOM: The pressure printed on the sidewall of the tire is the maximum tire pressure. It's printed there as a warning, meaning "if you put more than this amount of air in this tire, it could blow up." It doesn't mean you're SUPPOSED to put that much air in there. What a knucklehead!

RAY: It's like the maximum speed of your car. Your owner's manual may tell you that your car has an absolute top speed of 120 miles an hour. That doesn't mean the manufacturer is recommending that you actually drive it 120 miles per hour.

TOM: The pressure printed in the owner's manual, on the driver's door pillar, or the glove box door is the recommended tire pressure. That's the pressure at which the car handles, rides, steers, and brakes best. And unless you've changed tire sizes, that's the pressure you should always use. And for most cars, that pressure is between 28 and 35 psi.

RAY: Under no circumstances should you inflate your tires to maximum pressure. Not only will you risk a blowout, but you'll diminish your ability to control the car because your handling and braking will be much, much worse.

TOM: Not to mention the ride! How many scabs do you have on your head from bouncing up and hitting the ceiling since this guy overfilled your tires, Jon?

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