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-   -   What tire pressure do I keep in my tire? (https://www.ft86club.com/forums/showthread.php?t=111265)

VeganGirl 10-02-2016 06:13 PM

What tire pressure do I keep in my tire?
 
I have heard conflicting things...
I thought it is what is on your car when you open your doir(35psi)
Another person told me it's what is on the tire itself
A mechanic told me it is some sort of mix between what is on your tire and what your car says on the door
And my boyfriend said it is what is on the tire itself also


My rims rays gramlights 57xtreme
: front 8.5" x18
Back 9.5" x18
I don't know the other specs so I took a picture to better show as I don't know this lingo.
I haven't put air in them since I got them and I think that's probably bad but I don't want to explode the tire so any help would be nice )
Front:
https://i.imgur.com/FoxlECl.jpg

Back
https://i.imgur.com/UdnAvjn.jpg

swarb 10-02-2016 06:45 PM

Listed on the tire is usually max. You want to be below that.
Listed on the car is for stock tires.
Around 32-34-36 psi is a good starting point. You need to see how the tire sits on the ground or how it performs to decide what psi to run.
255/35 is a better tire size than the 265/40, which is throwing off your speedo.
You need a new boyfriend.

MarkR171 10-02-2016 07:25 PM

Quote:

Originally Posted by VeganGirl (Post 2766436)
Another person told me it's what is on the tire itself
A mechanic told me it is some sort of mix between what is on your tire and what your car says on the door
And my boyfriend said it is what is on the tire itself also

Terrible advice. The pressure printed on the tire is usually the MAX pressure you can safely run on the tire. Just follow the door jamb and/or owner's manual which iirc, is 35psi. Anywhere around 32-35 should be fine.

ryoma 10-02-2016 08:13 PM

keep in mind that you'll have more PSI when the tire is warmed up than when its cold. I usually aim for around 36/37 PSI hot and take it down to 34/35 PSI when tracking the car. keep a pressure checker in your glovebox (I have a digital one) so that you can check it every time you fill up since you're waiting anyways.

dp1 10-02-2016 09:29 PM

What's on the door (35psi cold pressure) for street including spirited driving - you will have broken many laws by the time your tires overheat on the street.

26-29psi cold pressure (~36-38psi hot pressure) for track, if you're planning to push the car.

VeganGirl 10-02-2016 09:29 PM

Thanks for the advise guys, I live in Florida so we don't have any weather extremes:)
I'll check what the tire says and make sure to stay below that

nextcar 10-03-2016 05:35 PM

With tires as wide as that in the front you may like the feel a little better if you bump the front tires to 38-40 PSI for the street, while keeping the rears at 35 PSI.

Note that Toyota USA biases the front tires to 38 PSI with the wider TRD 18 inch wheels/tires.

Note also that if you vary the tire pressure front/rear by over 5 PSI you may trip the TPMS system.

Hot and cold inflation pressures have nothing to do with weather variances! As you drive the tires heat up due to friction. The cold inflation values are generally taken as not having driven more than 15 minutes in the last hour or so!!! If you want a true "cold pressure" check your tires after the car has been parked overnight. Once you drive a couple miles at freeway speeds you will get hot pressure readings, not cold.

In the end, as others have stated the numbers on the tire are the absolute MAX safe pressure. The suggested tire pressures on the door jamb apply to the stock wheel size and tire size - the "correct" pressure is the result of the car's weight and the size (width) of the tire. There is room for adjustment due to personal taste (within reason) as well as very different guidelines for racing applications. Once you changed the wheel and tire size, the suggested tire pressures no longer specifically apply but are a reasonable starting point for experimentation. Monitor your tire wear patterns and adjust your pressure accordingly.

http://ls1tech.com/wp-content/upload...-patterns1.jpg

guybo 10-04-2016 06:37 AM

On the tire is printed the max cold pressure. Printed on the door jamb is the Toyota recommended based on what some engineer in Japan felt the best combination of wear/ride/balance would be.

Experiment with different pressures to find what works best for you sticking to within the max and about 30 psi cold pressures. The tire does affect ride quality and changing one end or the other can affect the balance of the car too. Plus like the post above, tire wear is affected.

The weather where you live makes a difference. In Florida, the tires will get much more heated than other parts of the country. Just drive down the highway and see all the gators on the sides of the road- blow outs happen all the time here because of running tire pressure too high.

8RZ 10-04-2016 08:04 AM

@VeganGirl Try eating meat.


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