how much air do i put into my tires?

Question

I have a 99 Chevy Prism does anyone know how much air i am to put into my front and back tires?

Answer 1

Check the door jambs or the owners manual for the recomended tire pressure. NEVER go buy what the tire itself says. It is a Maximum tire puessure when cold. That means the tire when it has been sitting and not used, should contain no more then that pressure, or an explosion hazard may occure. Use what is recomended by the manufacture, call a GM dealer if nessicary. DO NOT GO BY THE SIDEWALL. Most vehicles of that size are usually around 30PSI. I work in a garage, and I get many tires that are filled to max pressure, and everyone I drop down to the manufacture pressure, even if the owner wants it at that pressure. I do it because of liability issues. If it blew out and they found out that I knew the tires were filled above manufacture recomendation, I can be charged and be stripped of my Apprentiship licence, and be barred from the automotive trade. Always use manufacture recomendations and not the sidewall. Call a GM dealership if nessicary, look in the owners manual, check the door jamb, just don't go by the sidewalls.

Different tires are made with different materials. you can get the same tire size with many variables of maximum pressures, I've seen tires of the same size rated at 32PSI, 35PSI, 36PSI, 44PSI, 55PSI, and even 80PSI. The sidewall max pressure is only what the manufacure has designated the tire to opperate at a safe pressure or below.

Engineers do many calculations to figure out what the best pressure is. The do many calculations to fugure out what the best pressure is to give the best ride quality without sacraficing safty, or damaging the tires. There has been times when the calculations have been wrong in the past, but these problems have been made public knowledge as soon as the problems started occuring (firestone). If tires are over inflated by manufacture specifications, it puts strain on the center of the tire tread causing it to wear faster then the sides of the tread, ie. tire damage. If tires are underinflated to manufacture specifications, it can cause the vehicle to wander and be dangerious on the road. Every vehicle on the road has been calculated for the correct amount of air. If the tires are filled to something other, it can cause problems in the long run, that can be unsafe in some cases, and can be costly in others.

Answer 2

After speaking with a Yokohama Tire Engineer last summer I found It's perfectly fine to run tires at the max. pressure listed on the tires. Why would it be there if it wasn't safe? Case in fact. 2002 Pontiac Grand Am dealers recieved a factory notice to increase tire presures to 44 psi. on their B.F. Goodrich P-225 - 55 -16 tires. These cars were experianceing a serious brake grinding sound after people received full factory new replacements of GM brake pads and GM rotors.

The ride could be too harsh for some people. I recommend splitting the listed door pressure and tire max. tire pressure and inflate in the middle. The only reason car manufactures list that ridiculously low sloppy pressure is average people prefer average soft compliant ride. Inflate the tires to their maximum with nitrogen. Heat and pressures do not increase nearly as much. Added inflation eliminates the usual under steer or push while sweeping a curve. Try it and place a call to any tire company and ask customer service about max. tire pressures.

Answer 3

Ignore the tyre sidewall - this only lists the MAXIMUM pressure the tyre can take before it becomes dangerous. This is not the pressure you should run your tyres at - it is way too high, and will cause your tyres to wear out very quickly, give you a bumpy ride, and make the tyres more susceptible to road damage from potholes, etc. The tyre manufacturer doesn't know what kind of car the tyres were put on.

ALWAYS use the vehicle manufacturer's recommended pressure - you'll usually find it on a sticker, on the inside of one of the door jambs, but sometimes the sticker is in the trunk, or under the hood (rare.) Most cars will be somewhere around 30 psi, but I have seen as low as 26 psi, and as high as 34 psi. And it's not always the same for the front and rear tyres, either - so if you can't find the sticker, call your local dealership.

Answer 4

Generally, a medium sized car like your 99 Chevy Prism would need about 28 or 29 psi for the front 2 tyres and about 30 or 32 psi of air for the back 2 tyres. However, not forgetting the spare tyre in your car boot, it requires usually more air like 40 psi in case you need it for emergency.

Answer 5

It should prolly say the recommended psi on the tires towards the rim. Then just fill the tires with air and check them with a tire pressure guage thing until their right.

Answer 6

Look in your auto manual for recommended tire pressure.
Look at the side wall of your tire, it should tell you the recommended amount of pressure for that tire. Hope this helps.

Answer 7

the psi is usually listed on the tires themselves, the tires might not be original so its best to look on the tire sidewall.

Answer 8

it should tell right on the inside of your door.open the door and look on the end of your door.

Answer 9

it should be written on the tires.

Answer 10

usually about--------32lbs--