GPSman1:

How come nothing you state can be found in a owner's manual, tire manufacturer or at sites like TireRack? The only place that claims high tire pressure is correct is in the Crown Vic story or sites like this one! Oh, yeah, the one engineer too.

 

Modern tires for passenger vehicles are soft. They generally provide a nice compliant ride but somewhat shorter tire life. Tires only inflated to the recommended inflation will almost 100% of the time wear out on the sides of the tire. There simply isn't enough pressure inside the tire to put even pressure across the tread. Our hybrids, at least on those up to what is it '08?, have what I consider poor alignment specs also which contribute especially to early tire wear on the inside of the tires. I suppose that's really another issue. Tires like all other things have compromises. If you want max comfort and traction on dry surfaces, a really soft, low inflation tire will do that for you. You'll sacrifice fuel mileage and durability. On the other hand, you could put on these truck tires which are really overkill for our vehicles and get really good mileage as well as durability at the cost of soft ride and traction in certain conditions. As a previous poster mentioned, there are times when a stiffer tire is better for traction but certainly not all of the time, I wouldn't even say the majority. All this is somewhat generalized as there are so many variables which contribute to traction at any given moment, but I think it's sufficient for this discussion.

 

If you Google "proper tire pressure", you sure don't come up with anything suggested in this forum! How is it that Hybrid owners think that they know more the the automobile/tire manufacturer's and tire dealers???

 

It is because we are NOT in the business of SELLING tires!

If you sell tires, you want to sell more, more often, without being overtly deceptive about it!

We have had the technology to have light bulbs that last 100 years, for 100 years... but that would put the light bulb manufacturers out of business, now wouldn't it?

Try it for yourself. I'd never ask you to trust me.

 

I wouldn't waste my time!

It's simple. MAX air pressure mark on the sidewall of a tire is for MAX LOAD, it's marked right there also. If you not carrying MAX LOAD, you shouldn't run MAX air pressure.

If you go by the MAX air pressure marked on a tire, why don't you believe what a tire manufacturer states?

You don't put tires that belong on a F-350 on a FE/FEH either!

 

If there is one thing I've learned from all of the automotive forums I've been on, it is that tire and oil threads are always the most contentious. The problem is every body just knows that they know, but the fact is, there really isn't a wealth of empirical data out there, at least not that is readily available to you and me.

If you are going to be at max load, certainly you should be at max pressure. That is not the same as saying that it is dangerous to run at that pressure at loads less than max. The tire manufactures do in fact want your tires to wear out sooner. They also don't want you complaining of a harsh ride. They just have to sort of try for the middle ground. This doesn't even consider the CYA that all corporations try to do.

Consider if you asked the vehicle manufacturer what is the best speed to drive the vehicle. Obviously the MMH is perfectly capable of cruising at 75 mph all day long. Do you think the manufacturer is going to endorse this? Of course they aren't, they'd probably say something like 55.

BTW, gpsman1 is absolutely correct about the light bulbs. That is why it is illegal to import bulbs designed for the European mkt. I don't usually buy into the idea that corporations control the market, but occasionally, with the aid of BIGBROTHER, it happens.

 

After leaving a oil change place one day I noticed my '97 Ranger was riding harsh. A while later I hit a bump, hole or whatever. My rearend bounced into the next lane, lucky nobody was in that lane or I would have hit them. If I was next to the curb, it would have went over it and who knows what would have happened.

I checked my air pressure when I got home and it was way over inflated even compensating for hot tires. It plain dangerous to run high air pressure with no load.

Of course, I expect this from guys that tow 3500 lbs with a FEH!

 

Your suspension has more to do with keeping the tire in contact with the road than does air pressure. Not saying that air pressure has zero to do with it, just not as much as suspension. That is why sports cars have stiff suspensions.

 

Regardless, over inflated tires transfer road hazards to the vehicle. That's common knowledge.

 

You are correct. A properly damped vehicle (i.e. correctly valved and adjusted shocks/struts) will handle safely irrespective of tire condition. Pogo-bouncing is due to weak suspensions, not tires.
On a race track it is common practice to inflate tires to max rated sidewall psi to protect and preserve them under those conditions (and ensure consistent performance).