I have been a suspension and alignment specialist since the mid 1980's, but I have never heard of "lateral wear" related to tires. If the alignment is correct, under or over-inflation will cause less or more wear in the center compared to the inner and outer edges of the tread, that is all. The pressures are related to the weight of the car that needs to be held up. You have some rather large tires related to the small size of the car. That means you have a lot of square inches of tread contacting the road, so you need fewer pounds per square inch to support the car.
The more common symptom of low tire pressure is hard steering at low speeds, like when driving through a parking lot, and at higher speeds the steering response is reduced in panic situations. The symptom of excessive pressure is reduced ride comfort. That is what every manufacturer wants to avoid because rough ride does not sell cars.
If you are willing to give up ride quality to solve some other problem, you can safely go as high as what is molded on the sidewall of the tires. When I worked at a very nice family-owned Chrysler dealership through the 1990's, when I set tire pressures, if 35 psi was listed on the sidewalls, I set them to 35 psi, and when 44 psi was max, I set them to 40 psi. Over ten years I never had a single complaint of harsh ride.
Also be aware that replacement tires used to be available that were listed as "32 psi" max. Suppose your car came from the factory with 44 psi tires, and the best ride quality was achieved with 40 pounds of pressure, so that is what was printed on the door sticker. Now suppose you bought a set of replacement tires that were listed at 32 psi max. If you followed the door sticker and inflated those tires to 40 psi, they would be severely over-inflated and would be in danger of blowing out. Can you imagine the fun the lawyers would have with that? That is why the pressures listed on door stickers have to cover any available replacement tire.
Monday, November 21st, 2016 AT 4:02 PM