Just curious, how do you calculate proper tire pressure ?

Do you put it @ the max rate, as listed on the tire, or is there a rule of thumb to going below this. These are on 205/50/15 thanks guys

 

mines at 32 psi.

 

DO NOT inflate the tire to maximum pressure (the number on the sidewall)! You will run a very high risk of a blowout. Even if you don't destroy your tires outright, your ride will turn into liquid **** and your tires will wear unevenly. 32-35 PSI should be fine for a 205/50-15 712. I run all four corners at 35 PSI, personally.

 

Why would you "have a high risk of a blowout"? The max pressure listed is for the tire correctly mounted, pressure cold, at its max speed rating, at its max load rating. I can't see why that would increase the chance of a blowout. I do agree that it would hurt ride and probably decrease tire life due to wearing the tread down the center, unless the car is near the limit of the load rating.

For most cars, for street driving, within a few lbs of the factory recommendation is generally best. Even for significantly different than stock size tires.

 

it'd help if you posted the size of the tire, the car its on, stock tire size and stock tire pressure.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Mohudsolo &raquo;</TD></TR><TR><TD CLASS="quote">Why would you "have a high risk of a blowout"?</TD></TR></TABLE>

Because you are reducing your safety margin by inflating your tires to maximum pressure.

 

i still run stock pressure....

35 up front
33 in back

 

Other than mounting 3-piece trackter trailer tires, I've never heard of tires blowing up, or out, from running at the max pressure. I have seen lots of tires destroyed from low pressure. With too little pressure for the load, they overheat and fall apart. See Firestone/Explorer debacle. Ford spec'ed a pressure that was too low and blamed the tires.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by fivespeedintegra &raquo;</TD></TR><TR><TD CLASS="quote">i still run stock pressure....

35 up front
33 in back</TD></TR></TABLE>

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Mohudsolo &raquo;</TD></TR><TR><TD CLASS="quote">Other than mounting 3-piece trackter trailer tires, I've never heard of tires blowing up, or out, from running at the max pressure. I have seen lots of tires destroyed from low pressure. With too little pressure for the load, they overheat and fall apart. See Firestone/Explorer debacle. Ford spec'ed a pressure that was too low and blamed the tires.</TD></TR></TABLE>

somewhere between the recommended (adjusted for new size) and max would be best.

Say you run at max pressure (measured cold), and run the car hard, and on a hot day, and hit a bump that compresses the volume of the tire. All of these things add on to increase the tire pressure, even for an instant, a pressure that goes too high can blow out the tire.

 

a Kumho 712 should have a max pressure of about 44psi. that would be too hard to run on the street. I would reccommend in the 36-40psi range depending how you want to the car to handle. reducing the tire pressure too low on a performance tire will negate the handling and performance attributes of that tire. in my opinion 32 is too low for that tire on any car.....

 

Why would you "have a high risk of a blowout"?

most people that run this say 44 for instance don't realize that when their tires get hot and the pressure expands it does so by about 5 pounds. ask me if thats save.

not sure what some of these other people do from 9-5 but i work in tires. i would suggest to you at running 32-35 psi. you run higher then that you'll have problems with ride comfort, tire life, handling (to a point). you decide running lower then that you'll have run flat, terrible handling, terrible tread life, gas milage will be down a little also.