Quote:
Originally Posted by CapriRacer
(1)While I knew the marketing folks, I never asked them the question of how they determined the max
pressure, but I agree with you: Marketing. Fooling the public they are getting more than they actually
are. Not that it matters, because max pressure doesn't really mean anything. It seems to me to be a
case of telling a white lie.
But there is a thing about speed rated tires tested at more than 35 psi - and that's where the 44 psi and
51 psi came from.
Truck/Bus tires? They don't have a max pressure printed on the sidewall. They use this form: Max Load
XXXX at YY pressure.
(2)What I found was that many people think that the above way of stating the max load means that is the
max pressure, too. Sorry, but that is not the case. There are situations where a bit more pressure can be
used. It just isn't a hard and fast rule.
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(1) Which is why I've advocated for not listing any pressure on a tire sidewall. Drivers(at least non-commercial private ones here in the States) are mostly too ignorant to know where to source the correct pressure for their specific vehicle. And they take it so politically when you show them the correct way to set it. ,
So "Max Load XXXXlbs @ 44/51psi" on such a speed rated tire means the max load - at those higher pressures? As in, you can carry that max load at 35psi as long as you are maintaining speeds lower than the tires' full rating, buuut, inflate to the 44 rating if at speed? I can see where such reasoning, on part of the tire maker, could confuse drivers as to what the true "max" pressure is.
(2) Toward the end of this paragraph it looks as though you are saying it is ok, on occasion, to run tire pressures higher than the value on the tire sidewall, at least on the commercial side. Is that your assertion?
That might be why I read so many schoolbus forums where I hear about bus tires maintained at 110+? :o
Once in a while someone chimes in that they run 95psi cold, and both the bus ride and tire wear patterns are far more satisfactory. Someone - who thinks things through - a rare commodity in this new century!
Well, I'm still afraid to let folks I help, with tire pressures, know that their tires won't just explode at 36psi, or at 45, 52, or LT 81! That will only embolden them to use those sidewall values instead of the pressures carefully arrived at by the vehicle mfgs themselves.
They'll use the Ford "Exploder" case as rebuttal, not realizing that that was just one blatant outlier among mostly successful tire pressure recommendations. If more folks had observed the pressure offset specified on earlier Corvairs, we might not have heard - as much - from Ralph Nader.