tire presure recommendation

[speedyts49]

I have a set of mixed radials on my car. The front two are the same and the rear two are the same as each other. The fronts max psi is 44 and the rear are 51 psi. The recommended psi for this car is 38 psi max I think. I am wondering if I should put them close to the tire max or the car max psi.
My gas mileage has gone down since the people that aligned it set them to the car recommed psi.

[MR2Jedi]

what size are the tires?

[speedyts49]

I'll have to check in the morning but I think they are p195's. I get the rest of the info when the suns up.

[MR2Jedi]

profile hieght will determine PSI. I run 40 series on my MR2 and they take 40psi. pretty stiff but neccessary for low profile tires.

[cam2Xrunner]

I'd run them anywhere from 35-38 psi.

[dafunk_80]

This always confused me.. Like when it says MAX 35PSI do you really want to be setting it to the max? Usually I set mine to 33PSI,, and in cases where the max is 44PSI I set it to 40. Is that right?

[speedyts49]

Originally Posted by dafunk_80

This always confused me.. Like when it says MAX 35PSI do you really want to be setting it to the max? Usually I set mine to 33PSI,, and in cases where the max is 44PSI I set it to 40. Is that right?

A few years back Firestones were blowing right and left, front and rear for that matter and they tried to blame it on uninflaited tires. This is what I was thinking when I posted the question although I know when racing they do all kinds of things to the air presure.

[MR2Jedi]

if you will tell me the size tires you have and what make and model their on, I can tell you the correct tire pressure. I'll use my size for my MR2 Turbo for an example:
205/40 17 HR ,, the 1st #(205) is the tire width,, the 2nd#(40) is the hight- which is 40% of total tire surface,,, the 3rd# is the rim size it fits 17 inch,, and the last 2 letters(HR) are the speed rating-HR being 130mph-meanig you cannot exceed 130mph for more than 10 minutes or tire will become dangerously hot and could fail(lose cap tread, blow, etc.) hope this helps

[speedyts49]

Rears
Negotiator NH60
P195 60r15 8 7 h M+S
51psi max

Fronts
Lemans HR
P195 60R15 8 7 H M+S
44psi max

[MR2Jedi]

I'm guessing this is for the celica. probably 34 to 36 psi. here's a way you can get it perfectly. get some chalk and draw a line on the sidewall from where the tire tread ends to the rim. start at 34psi and then drive it around the block making sure you take left and right turns.stop and look at the chalk line. is any of it missing? if any has rubbed off the tire is too soft and flexing too much-you need more air. if it's untouched then you are ok. you can fine tune your air pressure from there by the way it feels too.is the ride too hard? or maybe too spongey? apply or deflate in 2psi intervals. I doubt they would take less than 32psi or more than 38psi..

[speedyts49]

yes sorry this is for the Celica. I would like to get optimum gas mileage and thought that if the tires were closer to max that it would improve. The car sticks to the road or has so far even when hitting the twisties so that is not a problem. I see having miss matched tires as not a good thing.