Different columnists are recommending different tire air pressures -- who's correct?

Dear Car Talk

Dear Car Talk | Jan 01, 1997

Dear Tom and Ray:

A while back, you guys told a reader not to inflate his tires to 44 psi (the maximum allowable printed on the sidewall). You guys said instead to use 35 psi (the pressure recommended by the manufacturer in the owner's manual). The same day, I saw an article by columnist Bob Sikorsky, who told a reader that he recommends the maximum allowable (44 psi in this case) pressure, because it provides longer tire life and safer and better handling of the vehicle. He said underinflated tires are much more dangerous. What is a lady with no car expertise to believe? -- Audrey

TOM: You should believe us, Audrey. Don't we look like sweet, honest guys?

RAY: OK, forget my brother. Don't I look like a sweet, honest guy?

TOM: Actually, Audrey, Bob Sikorsky has a technical point, but we're sticking strongly by our recommendation. You should use the manufacturer's recommended tire pressure in your tires, not the maximum pressure listed on the sidewall.

RAY: There is some marginal improvement in handling, braking, mileage and tire life at higher tire pressures, but in our opinion, they don't outweigh the significant reduction in ride quality.

TOM: When you inflate your tires to the maximum allowable pressure, you stiffen the tires, which is why handling, braking, etc., are a little better. But you decrease the tire's ability to absorb bumps and objects in the road. And as a result, you "bounce along," feeling every pebble in the road. Did you ever read "The Princess and the Pea?" Well, this is "The Princess and The T-Bird"!

RAY: Tires inflated to their maximum pressure are certainly uncomfortable -- as Bob Sikorsky, whose head probably bounces off the roof of his car on a regular basis, can probably attest -- but, in our opinion, they can also be dangerous in that they affect the comfort and concentration of the driver.

TOM: And the handling and braking benefits you get by using all that extra air are simply overkill on normal roads. On the racetrack, you might notice the difference. But at 25, 45 or 65 mph on city streets and highways, you're going to lose much more than you gain by blowing up those tires to 44 psi.

RAY: You don't want to underinflate the tires, either. But if Mr. Sikorsky is suggesting that using the manufacturer's recommendation is somehow "underinflating" the tires, then he's wrong. That's correctly inflating the tires, and it gives you the best balance of all characteristics; ride, handling, braking, mileage and tire wear. That's why the manufacturer, after great consideration, is recommending it, and so are we.

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