Originally Posted By: Ken2
If memory serves, you wrote one time that these manufacturer's stickers became accurate in 2006. What should one go by for an older vehicle? For example, my '01 Tundra has 26 psi on the sticker for the 265/70-16 tires.
This is quite complex, but allow me to refresh your memory.
I've noted 3 increases in tire sizing over the years. The latest was the result of the Ford/Firestone thing in 2000, and the upgrade was completed about 2006 - but this mainly applied to pickup trucks, conventional vans, and SUV's. Even then, some of those vehicles had reasonably sized tires, so it's hard to paint with a broad brush.
Cars were reasonably sized before that and the only change I noted was an upgrade in speed rating (with a couple of exceptions).
But in the meantime, the tires have gotten much better, so I don't feel very uncomfortable sticking with a simple, easy to remember: "Follow the placard".
Originally Posted By: JTSR71
Continental's tire selector specifies different psi's for same size tires depending on the load rating.
If you have a link to something specific, that would be helpful.
I did looked at their website and noted some situations where they differentiate between P metric and hard metric (and since they are a German manufacturer, I assume they are using the European standards), but that was only on plus sized tires, and there was only 1 psi difference - and I assume that's an artifact of the websites calculation algorithm, not something they deliberately put in because of the physics involved. (I'm thinking lawyers were involved, so they chose a "safe" path, rather than a "close enough" path.)
