The link
The problem with telling people to put in the recommended amount of air for the tire is that its not neccisarily the recomended amount of air for that vehicle.
Take for example the recent fun that was the Firestone/Ford Explorer debacle (even if the media did endulge a bit to make it more a news story than it was.) Firestone told customers to inflate tires to a certain pressure but because of whatever the reason (poor design most likely on the part of Ford) if you went with Firestones pressure, you ran a pretty good risk of flipping your SUV just TURNING.
On the otherhand Fords pressure was so low you ran the risk of riding severly underinflated tires in less than two weeks after you filled them.
The truth is that was Fords fault, but it also shows that the tire companies arnt always right either and given the choice of a blow out to flipping, I take the blow out (since I have had it happen once and while not fun at all, it was a lot better than the idea of being on my head) What people should really do is fill their tires to the recomended pressure on their inside doors (or in their manual) and check them every 2 weeks or so, like you do with oil.
Falcon,
I agree, the tire sidewall lists maximum pressure and load carrying limit for the tire. The placard on the car tells what the correct sized tire should be inflated to. Wider tires get less air pressure, narrower one’s get more, never to exceed the tire sidewall amount. The tire only lists what the maximum safe inflation for that tire is in any application.
I always ask when purchasing tires, and instruct others to ask also, most all the tire shops I’ve been to inflate ALL tires to 32 PSI. They don’t seem to even know about the placard on the vehicle.
My 1/2 ton truck has tires that are rated at 65 PSI, however if it’s not fully (or even a bit over) loaded running them at that high a pressure doesn’t leave must footprint on the road.
If you’re able to flip your car by just turning, I’m tempted to say that it’s a problem of the car, not the tires. Reminds me of the elk test where some swedish car testers managed to topple the then new Mercedes A-class when trying to avoid a crash with a hypothetical moose. The Mercedes guys simply had to get back to their desks to develop some electronics that solved the problem. It cost them 300 million marks. I guess Ford ought to do the same.
While Firestone had the pressures up (and made the truck tippy), Ford had the pressures lower… making them prone to blowouts and a rollover.
Each side blamed the other and ended a partnership that was started with the founders. (The CART race series uses Ford spec engines and Bridgestone/Firestone tires. I guess they made up.)
Ford did- the new Explorers have independant rear suspensions. The Explorer is one of Ford’s cash cows and was really hurt by the rollovers. It didn’t take them long to do something about it.
I guess so. Same goes for the A-class. I just checked it out on google, but most of the pages are in german - and 90% are jokepages on the incident. The funny thing is that some engineers claim that almost any car would have toppled in this test (which seems to be mandatory in Sweden - so I guess a Saab will stand it). But that didn’t make it less devastating for there sales.
I remember the Elk test. A similar test was done in the US by Autoweek Magazine with the Jeep Liberty and managed to almost tip it over (maybe they did). The writers said the tires gripped too much.
After denying design flaws, DC made a running change to the Liberty to lower it with lowering springs. Maybe they could have put some air in the tires.
No matter what manufacturers design, the owner will manage to wank it with bald, underinflated, overinflated tires. How can an engineer anticipate a kook running 50psi?
The most disturbing trend are these 20" to 24" wheels on trucks and SUVs. Most trucks are designed to use 16/17" wheels with sidewalls designed to plod cow pastures. How will these things react with 2" of sidewall on a highway dodging an “elk” at 70mph?
I remember the Elk test. A similar test was done in the US by Autoweek Magazine with the Jeep Liberty and managed to almost tip it over (maybe they did). The writers said the tires gripped too much.
After denying design flaws, DC made a running change to the Liberty to lower it with lowering springs. Maybe they could have put some air in the tires.
No matter what manufacturers design, the owner will manage to wank it with bald, underinflated, overinflated tires. How can an engineer anticipate a kook running 50psi?
The most disturbing trend are these 20" to 24" wheels on trucks and SUVs. Most trucks are designed to use 16/17" wheels with sidewalls designed to plod cow pastures. How will these things react with 2" of sidewall on a highway dodging an “elk” at 70mph?