“Common sense solutions to lowering your gasoline bills can go far. Carpooling, taking fewer or shorter road trips, and ensuring that your tires are fully inflated can all help stop the pinch at the pump.” ~Bob Ney
The other day I went to a repair place and asked someone, as a courtesy, to check the air in my tires. He did. He opened the car door, saw the suggested psi, and put 33 psi in each tire. I was annoyed that he looked at the car door instead of the tire. These were not the tires that came with the car. They were four matching tires I bought a couple of years back, and, frankly, I didn’t remember what psi was stamped on the tire. One of my children later looked and told me it was 35, so 33 psi is good.
To me, car manufacturers shouldn’t be allowed to post the psi at all, and mechanics should learn to ignore it. The psi is a tire thing, not a car thing.
Years ago I bought a mid-sized car with four pretty little tires, from an uncommon manufacturer. The tires were hard to find, but they perfectly matched the car’s specifications. Then something happened to one tire, and I had to replace it. I couldn’t find that particular brand, and I needed something now. So I bought a different brand tire, requiring a different psi. It had the same circumference, so there was no discernible difference; but it was bigger. Since it didn’t match, the repairman said, I shouldn’t consider this a permanent fix. I should replace it with a matching tire when I ran across the other brand.
The original little tires read 35 psi; the odd tire, 45 psi. When I put air in the tires, I put 33 psi in the three matching tires and 42 psi in the odd tire.
Now, you’re going to tell me, I shouldn’t run them that way. Who told you that? It’s not about the car: it’s about the tire.
Illustration: the donut (spare). No one suggests you use the psi on the car door for the donut, do they? The donut takes 60 psi. If you run it on 30 psi, it’ll collapse on you—bend over when you round a corner and come right off the rim.
If you are young, you may not remember the story of Ford and Firestone. There was a long working history between these two companies until tragedy and a lawsuit ensued. Ford had manufactured an SUV and mounted the suggested psi on the car door. But the 35 psi stamped on the Firestone tire did not match the 26 psi Ford posted on the car door. People were driving the underinflated tires, wrecking, dying, and suing Ford. Ford blamed Firestone; Firestone blamed Ford. Firestone had to take the hit when it was Ford that was calling the psi specifications. Afterward, Firestone had a hard time selling tires.
Fortunately, I never owned or drove a Ford SUV. But privately I had my own opinion. I had my own history of putting air in my own tires, and I pretty much did what I wanted to do. I never looked on the car door (still don’t). I looked on the tire. If a tire said 45 psi, I put 42. If it said 40, I put 37. If it said 35, I put 33. If the donut said 60, I put 50+. It’s the tire that has to be inflated, not the car, and the psi varies with the tire.
I cannot give you advice because I am not an expert. I’m a consumer like you. But a look at the donut or a look at the oversized tires some guys mount on their car should illustrate my point. Some tires make the psi on the car door look ridiculous.
“Inaccurate pressure can cause poor mileage, uneven tire wear, or a tire blow-out.” ~Anonymous
Copyright © 2013 Alexandra Lee