Runflats

[wormdoggy]

There has been much discussion on this so I will try to keep it as simple as possible.

The last topic on tire pressure, alot of you guys were planning to try tire pressure at 34PSI over the recommended 29PSI based on some track experiences by yellow32.

I received my car yesterday at 24PSI front and back. I thought this was kinda low so I asked my neighbour who is a mechanic and teacher . He told me to increase the tires to 45PSI front and back. Personally I think this is way to high and dangerous.

I would like to know what your experiences have been at 34PSI or do you still run tire pressure lower for normal driving on the streets?

This is very important to me since I believe the right tire pressure can save lives and keep us safe.

Cheers and safe driving.

 

[DSR207]

I keep mine at 36 psi cold. Better traction all around and more feed back, but Slightly rougher ride.

Tire max is 51 psi cold, so even at 45 psi it would be safe

 

[vipersrt10]

i think 45 might be good for the nonrun flats, mine at 38 are exihibiting serious sidewall flex and really hate them, but for straight line traction they are 10 times better than the run flats

 

[Skip White]

When the DC put the 29lb rating on the door, they really considered many factors, such as weight,tire volume, weight distribution, temperture, tire life, ride quality, safety at high speed, etc. The 29 is your reference point. The factory is trying to consider all factors and come up with an average. The tire says 52lbs max. What that is telling you, this is the most this tire can take at max weight capacity,(that's on the side of all tires) and not bulge in the center. They are by no means saying this is what to run in this tire. Only if you were at the max weight capacity of the tire. That's really impresive that this tire can handle that much pressure and not bulge in the center, but I'm sure it will bulge somewhat, if the car is not weighted to the tires max level.

Lot of room to play with, between 29 and 52 experiment and observe what works best. You may dip below the 29 in the rear if it helps tracion, ride, etc, but not to much in that direction, as handling, tire life, overheating, etc become a factor.

I had a Lotus Esprit, and the door said 23lbs for the front tires. As this car was a mid-engine car, and the tires were fairly large this was the correct pressure, and of course you could play with those numbers, but that was the reference point. The big rear tires on the car said 27lbs as the car was much heavier in the rear, and the tires were bigger. The oem tires on the Lotus said 52lb max pressure. The lube shop aired them up to that, and it only took one block to notice the mistake.

I know a lot of you guys own one of the new Dodge trucks (02 and up) and have the huge 20 inch oem wheels and tires on them. Let a lube shop air those 6 ply tires to max pressure of 45psi and see how far you can drive the truck. First patchy road you come to, it will bounce off the road. That huge low pro tire can not be ran with 45psi in it, no more than the truck weighs empty, especially in the rear. The door rating is even high, as they are considering the fact you may carry some weight in the truck, so they are averaging a psi rating.

Eperiment, bottom line, don't let the 52lb max rating on the tire confuse you. Dodge has given you a very well calculated psi number, experiment from that number, not so much the tire.

 

[wormdoggy]

When the DC put the 29lb rating on the door, they really considered many factors, such as weight,tire volume, weight distribution, temperture, tire life, ride quality, safety at high speed, etc. The 29 is your reference point. The factory is trying to consider all factors and come up with an average. The tire says 52lbs max. What that is telling you, this is the most this tire can take at max weight capacity,(that's on the side of all tires) and not bulge in the center. They are by no means saying this is what to run in this tire. Only if you were at the max weight capacity of the tire. That's really impresive that this tire can handle that much pressure and not bulge in the center, but I'm sure it will bulge somewhat, if the car is not weighted to the tires max level.

Lot of room to play with, between 29 and 52 experiment and observe what works best. You may dip below the 29 in the rear if it helps tracion, ride, etc, but not to much in that direction, as handling, tire life, overheating, etc become a factor.

I had a Lotus Esprit, and the door said 23lbs for the front tires. As this car was a mid-engine car, and the tires were fairly large this was the correct pressure, and of course you could play with those numbers, but that was the reference point. The big rear tires on the car said 27lbs as the car was much heavier in the rear, and the tires were bigger. The oem tires on the Lotus said 52lb max pressure. The lube shop aired them up to that, and it only took one block to notice the mistake.

I know a lot of you guys own one of the new Dodge trucks (02 and up) and have the huge 20 inch oem wheels and tires on them. Let a lube shop air those 6 ply tires to max pressure of 45psi and see how far you can drive the truck. First patchy road you come to, it will bounce off the road. That huge low pro tire can not be ran with 45psi in it, no more than the truck weighs empty, especially in the rear. The door rating is even high, as they are considering the fact you may carry some weight in the truck, so they are averaging a psi rating.

Eperiment, bottom line, don't let the 52lb max rating on the tire confuse you. Dodge has given you a very well calculated psi number, experiment from that number, not so much the tire.

Very informative, thanks for taking the time to write this.

Cheers

 

[Skip White]

One more thing, the oem tire pressure rating has also been tuned in with the suspension on the car. Suspension and tire pressure are both considered when they decide on what tire pressure to run.

The sidewall flex you are noticing doe's not nessesarly mean your car is handling worse.

When Nascar went from a bias to a radial design tire the drivers had a very hard time adjusting to the way the car drove. They claimed the car felt very unstable, but they soon became used to this, and it wasn't long before they said the new tire design was superior.

I seriously doubt that a runflat will out handle a conventional equal tire, but I'm sure the sidewall is stiffer in the runflat, and would make it appear to handle better. Those boat anchore tires can't even compare to a conventional tire. You should try balancing them on a road force balancer. They are loaded with heavy spots. Terrible, terrible tires, in some ways.