Tire Preassure Question

[Cpt Marvel]

I know that this would seem obvious. 2002 Accord 4cyl auto. Door frame tire preas says 29. Tires say 44 max. Lube place puts in 35. Tires are 195 65 15 89H Touring type. 29psi makes em look pretty low. Should I put that in anyway?

[EyesofFreedom]

No. 29 is too low on a 44 tire!

If max is 44 then 40 will give you the best economy but a somewhat rough ride. 35 Will give you a smooth ride but a little less mpg.

The best rule of thumb is to go about 4 below max that way you get a full contact patch of rubber---safety first!---and still have some room for expansion due to heat and rough road conditions.

[Cpt Marvel]

That's what I wuz thinking. Even 35 makes it look as tho not much rubber is on the road. Car's pretty light.
Thanks

[Zheka]

Guys what about hurting suspension on high-pressure (higher than recommended) tires.

[8695Beaters]

So Eyes, you think you know more than the OEMs about what pressure to put in the tires they designed for the car? It's not like they designed and built the entire thing (I don't mean to rip on you, but it's true).

If the tires are stock equivalent, then use the door jam pressure. That's what Honda meant it to have in it, so it would be stupid not to follow it.

Remember tire pressures change a good deal during driving. 40 psi cold will change to 47 psi or so once the tire heats up. Now you have shortened the life of the tire.

My dad puts 100 miles a day on his car (nearly all highway). He never uses any pressure but what Toyota reccomends for his Matrix. And his tires last just as long as they are meant to (60,000 for his last set).

[gxgman]

I have a 1997 accord EX with stock wheels and tire size. I have done a some experimenting with tire sizes and pressure. I lost an expensive set of tires (and several other average sets) to underinflation by following the recommended tire pressure. I found that 38psi cold provides the most even tire wear, so that is what I use. This is with 50% or higher freeway driving.
I haven't done much street driving until now, but I think adding any more than 2psi to this would be way too much. Small changes make a big difference. Of course, this is only with the stock wheels and suspension on my car. I don't think there is a set tire pressure for a set size. Too many factors effect tire wear and traction. It may be a matter of trial and error to find out what works best for your specific car, tire brand & size, driving habits, speed, etc.
Hope this helps.

[EyesofFreedom]

Originally Posted by 8695Beaters

So Eyes, you think you know more than the OEMs about what pressure to put in the tires they designed for the car? It's not like they designed and built the entire thing (I don't mean to rip on you, but it's true).

If the tires are stock equivalent, then use the door jam pressure. That's what Honda meant it to have in it, so it would be stupid not to follow it.

Remember tire pressures change a good deal during driving. 40 psi cold will change to 47 psi or so once the tire heats up. Now you have shortened the life of the tire.

My dad puts 100 miles a day on his car (nearly all highway). He never uses any pressure but what Toyota reccomends for his Matrix. And his tires last just as long as they are meant to (60,000 for his last set).

First of all the car is an 02 so it is unlikely they are the same tires as when it rolled out of the factory.Secondly this is a recommended tire pressure on the plate...not mandatory. Third is that the pressure max listed on a tire is what is known as "cold pressure" The tire is designed to run at max psi under max weight when checked cold...however it is extremely rare to max out the weight rating on the tire ever! And to answer you question, I am a retired mechanic...so I know about tires and recommended practices and uses...plus since then I have become a professional driver and recently was awarded my 1,000,000 mile accident free incident free award...and part of any good pre-trip inspection is a tire check!Under 80,000 to 100,000 pounds that I normally carry I keep my steers at max 110psi and all others at 100psi max...and have never had a blow out so a 3000 pound car will not have a problem running 40 psi in a 44psi rated tire!

[PrimeTimeV6]

LMAO!

[8695Beaters]

Originally Posted by EyesofFreedom

First of all the car is an 02 so it is unlikely they are the same tires as when it rolled out of the factory.Secondly this is a recommended tire pressure on the plate...not mandatory. Third is that the pressure max listed on a tire is what is known as "cold pressure" The tire is designed to run at max psi under max weight when checked cold...however it is extremely rare to max out the weight rating on the tire ever! And to answer you question, I am a retired mechanic...so I know about tires and recommended practices and uses...plus since then I have become a professional driver and recently was awarded my 1,000,000 mile accident free incident free award...and part of any good pre-trip inspection is a tire check!Under 80,000 to 100,000 pounds that I normally carry I keep my steers at max 110psi and all others at 100psi max...and have never had a blow out so a 3000 pound car will not have a problem running 40 psi in a 44psi rated tire!

Retired or not, I am going to make a guess that the engineers who designed the car know just a bit more about it than you do. They did after all perform all the calculations and design the car. You just fixed them. Again, not trying to be rude, but there is a big difference between repairing and creating. Yes, the pressures are marked as cold and they will rise once up to temp. My cold pressures are 25 and rise to 38 hot.

If you just ask any tire shop to replace the tires, they will use a stock spec tire. And while it may not be exactly the same, the tire size is not any different, so the presures don't need to be changed.

Good job on driving 1 million miles without an accident. We need more people like that on the road.

[PrimeTimeV6]

All the tire places I have ever gone to they always have used a generic 35 in regular tires or 40/45 in low profile and oversized tires.