|
Bob,
GY gave you part of the technically complete and correct answer. They are correct as far as they go.
What they FAILED to tell you in that e-mail is that every tire has a particular pressure that is suggested for a particular LOAD. They are assuming (and we all know what that does) that you are replacing like-for-like tires on your vehicle, and that the sepcs for any replacement tires are close to the original. That is a BAD (terrible in fact) assumption.
EVERY tire manufacturer has a "Load inflation Chart" for EVERY tire they make. What GY *should* have done was to ask you which tire of theirs you were asking about, and then send you a copy of the chart for THAT tire. All you need to know then is the load. That information IS on the door panel, and will always be correct (unless you exceede the mfgr weight ratings).
I have tried NUMEROUS times to get these charts from retailers (GY, FS etc, and independants like Tires Plus). All I get is a blank stare, and often the reply of "What, never heard of it." At that point, I WALK OUT.
The tire WHOLESALERS who sell and distribute tires DO have thses sheets, and I have them for the GY tires on my '89. The tires are Invectas (44psi), and to carry the maximum load in the wagon, I NEED 44 PSI. Therefore, the door sticker, for these tires anyway, is ABSOLUTELY WRONG. As an aside, the inflation chart also does not list ANY pressures below 32 psi. Hmm, that's MAX * 0.75. Interesting, the VERY same thing happens to almost EVERY tire on the road.
Exploders. Ford's suggestions are 26 PSI as I recall. The tires "MAX" = 35psi. Hmm, 75% again. AND they FAILED at that pressure. Too much load/speed.
You see, load and speed both do the same thing, generate heat in the casing. If you add load AND speed, you get BOOM! ala: Exploder.
Firestone TOLD FORD that if they insisted on the 26 PSI pressure, that they would need a tire with an additional belt (to reduce casing deflection and therefore heat). Ford rejected this, and people died.
Do what you want (everyone), but I daned sure will err on the side of safety, and keep my tires up to the MAX COLD when cold.
--
JohnG 1989 245 MT @ 235,000
|
