Car tire pressure

[ReductiMat]

Someone here must know the following:

Shouldn't tire pressure be dependent on the tire itself? Why should the door jam sticker know how much air pressure I should put in my winter tires? That said, there is no max/recommended PSI on the tire itself...

[Adam West]

tires dont know what car theyre going on. thats why your car tells the tires what psi to be at. not your tires what psi your car is getting.

[ReductiMat]

Gotchya.. it just seems not right that high-performance low profile 21 inch tires will have the same tire pressure as 18 inch winter tires.

[MackM]

Originally Posted by ReductiMat

Gotchya.. it just seems not right that high-performance low profile 21 inch tires will have the same tire pressure as 18 inch winter tires.

Which is why on the car it should list a recommended tire size along with the psi, when you stray from that use your brain.

[Adam West]

Originally Posted by MackM

Which is why on the car it should list a recommended tire size along with the psi, when you stray from that use your brain.

yeah pretty much this..

[OptionaL]

if tire size is outside of your car's manufacture recommendations, then typically take the weight of car divide by 100 then add 2 to lighter end and 4 to heavier end. i guess the reason for the car giving the psi is because different cars have various weights/characteristics.

example 3,000 lb. (3000/100) = 30 psi
lighter end = 32 psi
heavy end = 34 psi

then drive it and adjust to your liking i'd say.

[morgman]

A tire will have a Max Inflation pressure and a Max Load rating. If you take the weight of each axle and divide by two, that gives you a weight per wheel. Divide that by the Max Load to get a percentage. Multiply that percentage by the Max Pressure to get a number. Of course, if your owner's manual has a recommended inflation pressure for the tire size you're using, use that.

[ReductiMat]

Thanks all!

[Madman]

friend of mine swears by 50psi in his 31" tires on a toyota pickup because "It says so on the tire" the centers are wearing nicely and it rides like a shopping cart.

[KenN]

Originally Posted by Madman

friend of mine swears by 50psi in his 31" tires on a toyota pickup because "It says so on the tire" the centers are wearing nicely and it rides like a shopping cart.

Kick your friend in the nuts for me.

Please.


Kn.

[Madman]

Originally Posted by KenN

Kick your friend in the nuts for me.

Please.


Kn.

least he has come around to airing them down to 25 on the logging roads, made a word of differnce

[XXX_er]

Originally Posted by Madman

friend of mine swears by 50psi in his 31" tires on a toyota pickup because "It says so on the tire" the centers are wearing nicely and it rides like a shopping cart.

quite a few hyper miler VW TDi drivers put 50psi in their tires for less rolling resistance

they also drive around in 5th gear at 50kph to get high milage figures

This also clogs up their engines with EGR and pounds their bottom ends into dust

[PUNKY]

If you dent a rim add more air!

[hypa]

Originally Posted by Madman

friend of mine swears by 50psi in his 31" tires on a toyota pickup because "It says so on the tire" the centers are wearing nicely and it rides like a shopping cart.

I'm not sure what kind of Toyota he has, or type of tire, but my tundra has heavy 10 ply truck tires and I run 50psi. It's also a 5200lb vehicle, and I air down for the rougher trails.

[Madman]

Originally Posted by XXX_er

quite a few hyper miler VW TDi drivers put 50psi in their tires for less rolling resistance

they also drive around in 5th gear at 50kph to get high milage figures

This also clogs up their engines with EGR and pounds their bottom ends into dust

Dislike people that drive like that. When your motor clatters like its going to konk out when you shift, you should probably give it a few hundred more RPM between shifts. Same buddy with the 50psi tires will skip gears, IE, shift 2nd to 4th, then lug 5th from 50km/h to 90km/h, motor sounds so pissed when he does the 2nd to 4th.