I have done my research, too, what I have found out is that the Tire makers will always defer to the OEM Car maker's specs of the pressure, based on vehicle weight. Normally, the rule is: the same pressure originally specified is the minimum pressure required. Even of you change size of tires.

For example: If your car spec says 29, then the PSI is tied directly to the weight calculation by the CAR OEM. So, when you call each tire maker (this is so common), they will look at your OEM Car data and recommend the same, however, they would advise that a psi or 2 higher would be ok, never lower than OEM Spec. This will give you a bumpier ride, but will save your tire a bit longer. Do not go over 2 psi, as it will heat up as you run and will increase PSI in your tires a few more PSI, like 2~3.

 

What about lower profile tires? do their pressure needs change?

 

^yes. Low profile tires usually require more pressure than a normal profiled tire. I run 35-39 in mine...depending on temperature.

BULLMKT

 

i run 39 front and 35rear (both cold)

standard 205/65/15... any softer at front and ill be on the sidewalls during hard cornering

 

^yes. Low profile tires usually require more pressure than a normal profiled tire. I run 35-39 in mine...depending on temperature.

BULLMKT

I have Goodyear TripleTred 205/65/15 and I run 40psi day to day. They are rated to 44psi.

 

A good indicator on the max. pressure you can find on the sidewall of the tyre itself. Almost all tyres have that. I'd recommend to go near that maximum, since the recommended tyre pressure by the manual is way too low.

Why front and rear axle some users use different pressure is quite simple and you can experiment a little yourself. The motor is in front and most Toyotas are front wheel drive
(yayaya, old ones aren't) and thus the weight on the front axle is quite a bit more than on the rear end. I inflate my Corollas to 37 in front and 35 rear. If I'd go to 37 all around, my rear axle becomes very bouncy on uneven roads (and trust me, Montreal roads are the bumpiest you can imagine). Don't worry about a blown tyre because you inflate it hard. Most blown tyres are a result of UNDER-inflation. Of course, don't overinflate beyond the max. as per the sidewall, but I think that goes without saying.

Different pressure right and left I never heard before. Unless one regular rider is morbidly obese and weighs 350 pounds I can't imagine why this would be sensible. :lol: Sorry, couldn't resist.

Cheers,
Joachim

 

Tire pressure is based on a few things. Yes one is the wieght of the vehicle, and also he type and stifness of the suspension. If you run your tires too hard, you will put excess wear on the suspension. Too soft you will have a sloppy ride. The MAX on the tire is there because one reason......THIS TIRE IS NOT MADE FOR YOUR CAR, BUT A WIDE ASSORTMENT OF CARS. Different vehicles have different pressure requirements. It would not be very efficient or cost friendly for consumers to make a different tire for every vehicle out there. My point? Just because your tire is RATED for 44psi, doesn't mean that you should run them at 44psi, unless that is your manufacturers spec.
Left to right is if you are racing on a round track.

 

Tire pressure is based on a few things. Yes one is the wieght of the vehicle, and also he type and stifness of the suspension. If you run your tires too hard, you will put excess wear on the suspension. Too soft you will have a sloppy ride. The MAX on the tire is there because one reason......THIS TIRE IS NOT MADE FOR YOUR CAR, BUT A WIDE ASSORTMENT OF CARS. Different vehicles have different pressure requirements. It would not be very efficient or cost friendly for consumers to make a different tire for every vehicle out there. My point? Just because your tire is RATED for 44psi, doesn't mean that you should run them at 44psi, unless that is your manufacturers spec.
Left to right is if you are racing on a round track.

he meant if the tyre is rated for 44psi, dont go over it. that caps lock wasnt deserved...you just made a laughing stock of yourself if the tyre is rated for 44psi you really shouldnt go over 40psi as when they heat up youll end up being close or over 44psi anyway

get some chalk mark the side of the tyre at the tread/sidewal...go for a blast around ya favorite bit, park and check for wear.. if youre driving on the sidewall, time to inflate the tyres a bit more

 

The OEM tire pressure gives the best combination of ride (low psi) and noise.
Over inflating 4-5psi is a great idea on any car. More grip, Less rolling resistance.



Perfect example. A gen3 windom/camry/ES 300/bista calls for 32psi all around.
Toyota/Lexus of Europe specifies 38psi all around for autobahn driving above 90mph.

I like 38-40psi.

 

FWIW...
The heat/pressure buildup in road tires is very little.

My grandfather (A 40 verteran of the Goodyear - Gadsten plant - master oiler/engineer) Told me years ago that Goodyear use to do testing the the deserts of the southwest to test road tires. The differance pressure build up between a tire in Akorn on a freezing day, and a 90+ desert day at 60mph was less than 1psi.

 

Hm... my Insignia SE200s are rated 42 or 44 (I forget), but I don't remember who last checked my tire pressure but when I went back to check it again, it was at 52PSI. And I was running on it like that for a few months. Granted, I did check it when the tires were hot, but I was surprised nothing was happened. Waited till cold and lowered it back down to 30PSI manufactured recommended, but it feels REALLY different, and not in a good way.

But at 52PSI, I must have been hurting some inner tread. I'll do the sidewall chalk thing sometime tomorrow.

 

he meant if the tyre is rated for 44psi, dont go over it. that caps lock wasnt deserved...you just made a laughing stock of yourself if the tyre is rated for 44psi you really shouldnt go over 40psi as when they heat up youll end up being close or over 44psi anyway

Actually, 44psi is the max. cold rating on the tire NOT the MAX pressure. The cap locks were to make people aware of a point that is far to often overlooked. People say time and time again that "my tires are good for 44psi". Did you build this car? You know more about tire pressure than the engineers that made these cars and specify a certain pressure for best wear, least noise, and wear on the suspension? If so then I'm sorry, but VERY unlikely. I've done some reading on handling, and tire pressure is a big factor in this. People assume that harder tires handle better, this is not true. On avg. the best psi for handling is about 33psi(and yes this is for track driving), again this is an avg./generallization, so it is not exact, but deffinatly within 1-3psi. So exuse me if I am trying to help with some of my knowledge, and as far as I'm concerned I have not made a laughing stock of myself. And if you think that I have thats fine becuase that is your opinion, and you have the right to it. And just so you know, opinions like that mean nothing to me

 

The OEM tire pressure gives the best combination of ride (low psi) and noise.
Over inflating 4-5psi is a great idea on any car. More grip, Less rolling resistance.

More pressure leaves less tread contacting the road, so therefore not better for grip. You are correct in stating that it will have less rolling resistance.

 

I run somewhere around 30-32.

What is the accepted loss of pressure over a period of a month?

 

I think my Gen 5.5 says to use 29 psi the whole way around.

I would like the tires to be a little higher than that because it stops me from squealing around exit ramps.

I have started running them at 33psi the whole way around. I only have 3000 miles on it now and I don't see any odd tire wear (like the center burning out) yet. Any idea how to tell just how high you can run them before you cause uneven treadwear??

I ran the Dunlops D60 A2's on my old Gen 3 too high and burned the centers out. I think I had them up at like 38psi though. I don't want to do that again.

The guys at my local tire shop won't say anything other then check the door plate and ONLY run that PSI (wussies)

 

my book says 30psi, the dealer puts in 35psi at oil changes, my sidewall says 44 psi max cold (cold meaning your car hasn't moved for at least 3 hours, and no more than 1 mile).

I keep them at 40. Gas is expensive in Cali.

 

Actually, 44psi is the max. cold rating on the tire NOT the MAX pressure. The cap locks were to make people aware of a point that is far to often overlooked. People say time and time again that "my tires are good for 44psi". Did you build this car? You know more about tire pressure than the engineers that made these cars and specify a certain pressure for best wear, least noise, and wear on the suspension? If so then I'm sorry, but VERY unlikely. I've done some reading on handling, and tire pressure is a big factor in this. People assume that harder tires handle better, this is not true. On avg. the best psi for handling is about 33psi(and yes this is for track driving), again this is an avg./generallization, so it is not exact, but deffinatly within 1-3psi. So exuse me if I am trying to help with some of my knowledge, and as far as I'm concerned I have not made a laughing stock of myself. And if you think that I have thats fine becuase that is your opinion, and you have the right to it. And just so you know, opinions like that mean nothing to me

perhaps you didn't make a laughing stock about yourself, but you clearly show that you only accept one opinion - yours and try to ram yours down the throat of everyone. Is that necessary?
Besides, you are contradicting yourself in a big way. In one post you write it all depends on the individual car, and that is a point, above you write 33 psi as a general.
Neither is true.

Fact is that every tyre maker will tell you (send them an e-mail and aks) that it's better to put about 5 psi more into the tyres than recommended by the manual. That's what I have been doing the last 8 years with the (not so) surprising results that I had very even treadwear.

And yes, harder inflated handles better, but of course there's a limit from which pressure onwards the handling and grip gets worse again.

Cheers,
Joachim

 

Tire pressure on trucks

On a truck (Im talking a real truck, not an SUV) there is a big different in weight balance from the front to the rear.
A truck has the majority of it's weight on the front tires. Therefore, if you have the front and rear tire pressure the same, the front tires will wear more because they will have more "squish" to them which will result in more of the tread being in contact with the road. This also causes the tires to run a little bit hotter, which also increased tire wear.
Let me use my F-150 as an example. Ford states that you should run the tires at 35 PSI. I run my tires at 40 PSI front and 35 PSI rear. I have no problems with tire wear. In fact, I just recently had to buy a new set of tires. When I bought the truck, it had 69,000 miles on it and has the tires it came with from the factory (I know this because the previous owner left me his maintenance log in the glovebox). I just recently replaced them and they had about 90,000 miles on them.
I admit, I do run my tires a little bit high on airpressure. However, I also get excellent fuel economy and tirewear.
The biggest thing with air pressure is to just look at how the tire is wearing. If it looks like the edges of the tires are getting a little bit too rounded or "cupped", put more air in them. If it looks like the middle of the tire is wearing a lot, take a little air out of them.
Myself, I would prefer the middle wear over having the sides wear. I live in Wisconsin, so I have to drive in snow about 3 months out of the year. The less wear I have on the sides of the tread, the more control I will have in the snow.
Cap'n

 

They are rated to 44psi.

And mine to 51. :lol: :disappoin Now mine are running 47psi.

BULLMKT

 

perhaps you didn't make a laughing stock about yourself, but you clearly show that you only accept one opinion - yours and try to ram yours down the throat of everyone. Is that necessary?
Besides, you are contradicting yourself in a big way. In one post you write it all depends on the individual car, and that is a point, above you write 33 psi as a general.
Neither is true.

And where exactly do you this this idea that I accept only one opinion. The only opinion that I disregarded was the one that stated I made a laughing stock of myself.

as far as I'm concerned I have not made a laughing stock of myself. And if you think that I have thats fine becuase that is your opinion, and you have the right to it. And just so you know, opinions like that mean nothing to me

And try to "ram" my opinion "down the throat of everyone". Try to read carefully before you start insulting people. That is absolutly rediculous. That would be like me saying that your comment.....

Fact is that every tyre maker will tell you (send them an e-mail and aks) that it's better to put about 5 psi more into the tyres than recommended by the manual. That's what I have been doing the last 8 years with the (not so) surprising results that I had very even treadwear.

clearly shows that you only accept one opinion - yours and try to ram yours down the throat of everyone.
I don't actually believe that, but just making a point.

In re: to me contradicting myself.....It does depend on the specific vehicle.
Do you understand what an Average is? If so you may better understand that this is an Avg. tire pressure, not exact as I had stated before. Depending on the specific vehicle it will be within a few psi of that range. Given, there are some exceptions that don't fall into that range, but most vehicles do.(our Toyota aren't one of the exceptions that I am aware of anyways). And I have actually read several books over the years in re: to tire pressure and how it effects handling. Where are you getting your info. from? The guy selling you your tires? Who else?

 

roc, you remind me a lot of a guy from Hong Kong who loves to use quite strong words to others but is extremely sensitive to receive them in return. (I lived there for 14 years, just want to avoid that this may be misconstrued).

Picture this. I had a car (Alfa Romeo) in Hong Kong and mounted 17" tyres onto them. 215/45 R17. My choice then was Goodyear F1 Gs 02. Since the manual did not specify the size, I sent an e-mail to Goodyear directly, asking the tyre manufacturer, giving them the car specs. etc.
They very kindly replied and recommended 37-38 psi. That was a whopping 6 psi over the manual which stated 32. And, btw. they really looked like almost flat if only inflated to 32.
Next set was a Dunlop SP 9000. Again I thought it wise to ask the manufacturer and they came back with 37 psi, too. Now, next thing, my friend, identical car, bought a set of Avons, I think they are called ZZ-1 and they were far too hard if inflated to 37, so we lowered to 34, which incidentally Avon confirmed as the pressure they'd recommend.

The point I'm trying to make? There is no such thing as a 'G e n e r a l' rule. Tyres are made in different ways, and I agree with you, have to fit a great number of cars. But since the flanks are in different ratios and some are softer, some are harder, to say there is an average won't do.

I would like to add that all three tyre makers, Goodyear, Dunlop and Avon stated that the recommendation of almost all car makers are way too low and an increase of 3-5 psi over the manual would be more realistic.

Lastly, someone here recommended to put a chalkmark to the flank and push the car into a curve, then see how far the car is driving on the flank. Try it, you may be very surprised that
you may only be half inch away from hitting the rim to the ground in a hard driven corner.

That's all I have on this, now argue all you want, I rest my case.

Cheers,
Joachim

P.S. My 03 Corolla I just bought second hand has Tyfoon Successor tyres on it, they suck big time. Anyone wants them in Greater Montreal. I'm changing them soon to something
I'd call a tyre. Those are like a disease.

 

The point I'm trying to make? There is no such thing as a 'G e n e r a l' rule...

This thread has caused me to do some research. I forget where this info came from, but I did stumble upon this formula in my searches.

PSI = (Vehicle Weight in lb/100) + 2 psi at heavier end + 2 psi all around if suspension and alignment are stock.

Example: Stock 911, 3,000 lb.
(3000/100) = 30 psi
Add 2 psi all around = 32 psi
Add 2 psi to heavy end = 34 psi at rear
With modified suspension, the result is 30 psi front, 32 psi rear.


I haven't worked any numbers on my own yet with my cars to see where this leaves me, but this is an interesting formula and appears to be generic.

 

At the dealership we just set the tire pressure at 32psi all the way around.