i have 215/45/17s on my 88 right now. i know the recommended psi is 32 but should i put more in with the bigger wheels?

 

Maybe just look on the tire? It will tell you the max psi. I usually go a little lower than the max. Once they warm up the pressure goes up.

 

32 should be fine.

 

Completely depends on the tire. My current tires have a max of 51 psi, while my old ones were 45. Keeping it near the max will ensure the best handling/fuel economy.

 

the max psi is usualy for instulation of the tires. if you are running drags then run lower preasures on street tires like 20. if your street or track or auto xing then just run 32 and you will be fine. if you run anything above 38 then you will get tires that wear in the center of the tire and not a very good contact patch

 

NO NO NO NO NO NO NO NO. Not on a street driven vehicle!

Over inflating a tire (which if you are putting it near the max PSI- you are over inflating) will:

#1 Wear the tire out faster
#2 Wear the tire out un-even (typically the center tread will wear out before the side tread)
#3 Radically reduces traction in wet, and dirty locations
#4 Reduce traction on bumpy/grooved roads.
#5 Overheats the tire and can lead to tread/cord separation.
#6 Reduces the contact patch leading to lower overall traction in dry situations.
#7 Can more easily cause or be in Blow out situations.
#8 Higher inflated tires cannot isolate road irregularities as well causing the vehicle to ride harsher and transmit more noise into its interior.

The tire needs to be inflated to a point that it can still absorb the irregularities of the road, and for even tire wear. The max tire pressure is for seating the tire when installing it. It is not what you ever should be driving at.

A good rule of thumb for setting tire pressure is for each Plus series (for example a 17inch tire is two plus series over a 15 inch) add two PSI to what the factory recommends on the tire inflation plate in the car. Also add two PSI for high speed driving (such as more than 85MPH) and add 2 PSI for a firmer ride (if ride is not that important). So in this mythical situation of a Plus two, up from a 15 inch that the factory recommends 26 PSI, 34 PSI would probably be max.

Therefore if the factory suggests a 26 psi on the 15 inch tire, you could add up too 8 PSI MAXIMUM for proper handling on the street using a 17 inch tire/wheel. But if you start seeing uneven wear (like the center tread is wearing out faster than the sides) then you need to adjust the air pressure down. If you start seeing the sides (and both sides, not just the inside edge or just the outside edge) wearing more, then you need to add a little more air pressure.

 

I've got goodyear eagle f1's i have 215/40/17's and im running them at 34 right now. they max out at 51. Read what icemark says it is very good.

 

Can't beat Icemark's description here. I work at a Wal-mart Tire and Lube center, and I've seen it both ways. A lot of people with low profile tires on their cars seem to want to put an enormous amount of air in it. The most I've seen so far is 65 psi in a tire with a max inflation of 50 psi.

Putting all that air in it will just give you a shitty handling tire and the inside tread will be showing belts before the outer tread hits the wear bars.

[edit] Thought I'd throw in that I run 35 psi in my stock size tires. I've been getting reasonably even treadwear, which I do bother to measure every so often. I was running 32 psi, but they would handle like crap on wet roads. After adding 3psi they run fine. (205/60R15 Uniroyal Touring Trak)

 

thanks for the responses guys, great input! i think ill try 36 and see what happens.