Tire Pressure

[riojin]

i have 14x6.5inch rims running 185's. i was previously running 38psi presure in the tires all round (i was running this for a month and even with my driving and all the pot holes and speed humps they didnt lose any presure).

tonight i decided to firm it up. i went for 44psi front and 40psi rear. i was suprised how much difference it made. I'm sure the difference was noticed because of the higher presure in the front.

i am now much more confident with my cars handling. corners where i would enter at 130km/h i can now enter at a higher speed and feel more safe.

what presures do you use?

[ae71]

holy shit, what car is that a truck?


for a car of this weight the recommended pressure would be about 30psi

i run 28psi in the front, same sized tyres and wheels as you and about the same in the rear.

for spirited driving i sometimes drop the front pressure to 25psi same with the rear.

for drifting i up the rear pressure to about 30psi


remember all pressure is cold as warm tyres increase the pressure.

id say that is way too much pressure and you will probaly find as your tyres wear that the middle will wear much faster and it wont be even. perhaps for max tyre life and minimum fuel consumption with mostly highway driving then maybe 35psi which would be good for towing as well.


try dropping the pressures to something like i run and try the brakes. the lower pressure provided a larger contact patch with the road. with lower pressure you will get a bit more tyre roll but with a sports orientated tyre with a stronger sidewall than the $65 maxi grip tyres that you find on the rubbish tip they should have stronger sidewalls to start with.

[Fozz]

40 is not that crazy

recomended pressure in my tyres is 32

but i run them at 38

[pebbles]

i run about 33 in the front and 35-40 for the rears

13X6 wheels
175 front and 165 rear tyres

[Moebius]

I run about 40-42psi if the tyres can handle it.

[ke70dave]

195/50/R15's all round, 33-35 in each.

i find if its much less you can feel the tyre moving around, just not as direct feel.

why do you guys run such high pressure? is it cause you are trying to make it drift or something?

[Moebius]

<div class='quotetop'>QUOTE (ke70dave @ May 25 2008, 10:00 AM) </div>I forgot to mention that's not cold pressure, but warm. I run that pressure because that's just what I have found suits me best. It's nothing to do with drifting.

[ae71]

perhaps to save as much fuel as possible?

i love to have grip, i find with higher pressures feels like the front end is going to slide off the road and with proper sized (not over sized) tyres i don't seem to feel that there is excess tyre roll.

a lot to do with your set-up, personal preference and what your doing/want..

[sly1300]

shit. way too high.

measured when cold... and for daily driving

32-34 in the fronts
30-32 in the rear.

lower the pressure = more grip
wanna skid? = pump up your rears

and always put the best tyres you can afford. seen so many nice cars let down by a cheap shit set of fuckin nankangs or wanli's.. remember theres only 4 little black squares of rubber holding you on the road, and you want the front to go where you point it.

i never realised tyre pressures made such a big role until my first drag street meet many years ago
couldnt work out how similar powered cars were eating me over the 1/4... kept upping the boost for more power and all i got was more wheelspin... spoke to some boys in the pits, dumped 15psi from the rears and WHAM instant traction, well less wheelspin than before


then busted axle slapping third

[archangel62]

<div class='quotetop'>QUOTE (sLy1300 @ May 26 2008, 12:59 AM) </div>x2.

Except I run 32-34 in the rears and 30-32 in the fronts because my tyres are getting old, and oversteer > understeer.

I dunno why you guys are running in the 40's, it's killing the tyre and unsafe, giving you smaller contact patch too. The only good thing it's doing is making your effective "springrate" higher, because on 13"s for instance, half of your "suspension travel" is just sidewall flex. If you want to firm up, get stiffer springs, or 15" rims. 195/50R15 inflated to 32psi is a much better idea, seriously. I even noticed the difference dropping from 36 all round to 32-33. And just from a bit of spirited hills, you can expect tyre pressures to jump 3-4psi.

Sidenote - most servo tyre pressure gauges are ratsh*t. You can pump to 32psi at one, drive around the corner and the next one will tell you you're at 28psi. Tip - get a cheapo analogue gauge, I got mine for $2 from cheap as chips, and when you get new tyres ask the tyre place what they inflated your tyres to, then test all of them with your gauge. Even if your gauge is out, it will be consistent. Saves you running "miscellaneous" pressures at servos.