Tyre Pressure

[ironpaw]

Just wondering what everyone's running on their boats.

When I had new KU31's put on (245/40/18) my steering went all heavy and crap at low speed. At first I thought the tyres must be underinflated...

Went to the servo, fronts were at 34 and rears at 36. Pumped all 4 to 39(!) Is this too high?

Now I realise the increased tyre width probably has more to do with it....right?

[Sunkist]

mine are all at 38.. and mine feels pretty stiff to steer. i think its just the dimension of wheels bud.

[zei20l]

read the pressure rating of the tyre. it will have a maximum. but too high will cause excess wear in the centre, an underinflated tyre will wear onthe outside.

a too firm tyre will be bumpy, especially with aftermarket suspension. i think i run mine at 38 front and 36 rear. but this is when cold. always check when cold

[iamhe77]

40psi front and rear.

Better handling and slightly better economy

[rosella]

I run 38-40 front and 36-38 rear. Definitely makes a difference to both handling and economy.

[Daleo]

40psi front and rear.

Better handling and slightly better economy

Same here

[Global_Warmer]

I was runing 34psi but after a run down Putty road on the weekend it was too rough with the coil overs. So on the return trip, i lowered em to 28psi. Car was much better to drive and not quiet as rough. Still handled the corners beautifully!!

I run these tyres: http://www.falkentire.com/Tires/Passenger-Car/Azenis-RT-615K-14

[ironpaw]

ahh ok so 39 all around aint too bad then...LOL

[prince_skyline]

40psi all round here too. Rolling on 19's

[pipster11]

you can put a line of whiteout across the face of the tyre and it should wear off evenly

if it goes from the middle first - too much pressure, from the shoulders - too little

[SMOKEYV35]

i like that test.

but yep, i run 38 front and rear - tested when cold.

good investment is a digital pressure gauge. dont trust the ones at the servos. i check pressures weekly. car feels nicer and less jittery over low speed bumps when the pressure is down around 36 (which is what most tyre places will reccommend) but i reun a slightly higher pressure to protect the wheels, and to counter some of the camber wear by rounding the center of the contact patch.

[scotty nm35]

Just wondering what everyone's running on their boats.

When I had new KU31's put on (245/40/18) my steering went all heavy and crap at low speed. At first I thought the tyres must be underinflated...

Went to the servo, fronts were at 34 and rears at 36. Pumped all 4 to 39(!) Is this too high?

Now I realise the increased tyre width probably has more to do with it....right?

I run 38 - 40psi but I believe your heavy steering is caused by the wider rims/tyres and different offset. It gets worse the wider you go.

[ironpaw]

well good thing I didn't go 9.5"!

[bangahh]

Usually 40 all round

[bubba]

That's all horribly low for low profile 18's...

I run my 235/40/18's at 45psi cold, even 42psi doesn't feel right and anything under 40psi feels terrible.

[Global_Warmer]

That's all horribly low for low profile 18's...

I run my 235/40/18's at 45psi cold, even 42psi doesn't feel right and anything under 40psi feels terrible.

You must have good suspension to compensate your tyres which are as hard as concrete!!

Must be bloody slippery in the wet/rain with those pressures.

[Ten Four]

I also run 40 psi all round in 255/35/17s.

If I know I'm going to be smashing it, 50 will be what I run.

Will say though, that my car isn't a daily, already has rock hard suspension and no rear seats

Edited April 7, 2011 by Ten Four

[SMOKEYV35]

50psi!? that is ridiculous. and why would you run it higher if you're lashing it? should be running it lower if anything. otherwise it just turns into a roller skate - you will get better grip with lower pressure, plus it will allow for expansion of the air as the increased heat levels build.

only people i know who run those pressures are the VIP guys who run super stretched tyres and huge camber - helps prolong tyre life and keeps the tyre seated on the bead.

[Ten Four]

50psi!? that is ridiculous. and why would you run it higher if you're lashing it? should be running it lower if anything. otherwise it just turns into a roller skate - you will get better grip with lower pressure, plus it will allow for expansion of the air as the increased heat levels build.

only people i know who run those pressures are the VIP guys who run super stretched tyres and huge camber - helps prolong tyre life and keeps the tyre seated on the bead.

no

Should mention, I don't have a stagea and just realised this is the stagea section..

Edited April 7, 2011 by Ten Four

[zei20l]

on drift days you run a higher pressure in the rear. also some tyres are rated to 50psi. i remember a set i had on my S13, 52psi was the maximum. i ran them at 44psi.

if 50psi is over the maximum rating, youre taking a risk IMO