Tyres Pressure On 18'' Wheels Anyone ....

[BigBoyLemonade]

On my 19's I run no less than 40psi and try and keep them at 45psi.

[Noble323]

Originally Posted by Savvyfx

any response from the manufacturer?

Okay nothing from Kumho yet, but (i didnt know why i didnt think of this) i called Kumho :

National Head Office
147-149 Gilba Road
Girraween NSW 2145
Tel: 02 9631 7111
Fax: 02 9896 1537

Spoke to STEVE at Kumho and said to pump them at 32psi and told him that they look flat if at 32psi, then he suggested at 36psi and i told him i have them at 38psi and said it should be fine, and said do 38psi front and 36psi back to level it out, so it helps when braking, but said originally its normally pumped at 32psi and depending on different cars its different psi.

He also said its better to have more pressure than less, and its best to call the tyre manufacturer to get the right pressure for your car.

So that answers my questions and hopefully some of yours

[geetee]

I have 215/35/18 on my BJ and they're at 32psi.
Tyre place recommended not straying too far from standard tyre pressure.
They look fine, feel good and the car handles perfectly.

Why do we want ot go up into the 40's???

[Rupewrecht]

What's the load rating on the Kumhos?

Ive normally got my 17's around 40psi. Higher for long trips.

[Noble323]

Originally Posted by Rupewrecht

What's the load rating on the Kumhos?

Ive normally got my 17's around 40psi. Higher for long trips.

Okay the spec's are :

215/35ZR18 - 84W
Max Load : 500kgs (1102LBS)
at 300kpa (44PSI) Max Press

[Rupewrecht]

That's under the load rating for the car then - which would be part of the reason that the pressure is lower than something with an 87W (which would be legal)

[phoenix.v2]

just a quick note for those who are reading this....

manufacturers tend to recomend 34psi cos thats what they set it at. the reason being is that it gives a smoother ride (you dont feel every little bump in the road).
if you want better handling, bump it up to the high 30's, low 40's range (depending on tyre type and wheel size). that way you will get better handling.

alltho, you will feel every single bump in the road! not that that bothers me =b

[RedLineResident]

I run 16s at 36 - 38 front 35 -37 rear.

i find too low a pressures will roll and understeer, too high a pressure are slippery as hell, especially on change of direction and it is very unpredictable when its at the back axle.

The less meat a tire has the higher the pressure you need in it. 18s I don't know but i wouldn't have anything less than 40psi, thats for sure.

[RedLineResident]

Also ride quality is s*** when pressures are higher. You notice when you go to buy a car from a car yard the tires are a bit lower. The car feels more comfortable, less road noise, and bumps feel milder. (NO I DON'T OWN A CAR YARD)

The problem is tho, lower pressures roll onto the edge and destroy the tirewall when pushed hard enough. Wear faster and cause more resistance hence you use more fuel.

With no Power steering you really know when the tire pressures are down, the bastard feels so damn heavy.

[89sp1.8]

my opinion is i would havew them at min 40psi prob more like 42-44 pumped.i usually pump up to just below max pressure stated on wheel..good luck

[Bear]

something you all would have noticed after reading the thread is the little fact that tyre pressures aren't an exact matter ... they're highly subjective ...

if you are looking at having a more comfortable ride and aren't looking for highway economy, or performance handling ... run them at anywhere between 32 and 38psi ...

for slightly better handling, and old suggested level is 38/36 front/rear ...

but if you're looking at getting the best performance characteristics from your tires, you will find that you need something in the order of 38 - 40 psi(possibly even higher ... depends on what the tyres can take) ... I used to run 40 psi on my 215/35x18s ... I found that perfect

honestly ... try starting at 32 as they originally were ... then gradually try a couple of psi more each week and decide what feels and works best for you

[zappy65]

i have 16's i put 42 in the front and 38 in the rear, i believe this helps understeer, dont go on "if the tyre looks flat" it all depends on the load and conditions, if it rains you want them to be around 34psi so you can get more tread to the tarmac etc. Tyres are a big mystery, some people belive that big block patterns tend to "feather or scallop more" and some believe the total opposite, the best thing to do is compare your tyres to your driving style and adjust accordingly...oh and remeber tyre pressures rise and expand when the tyre gets hotter!
having more pressure prevents the side walls from collapsing, if the tyre pressure is too low the side walls will collapse leaving you with a structurely unfit tyre!

[geetee]

Originally Posted by geetee

I have 215/35/18 on my BJ and they're at 32psi.
Tyre place recommended not straying too far from standard tyre pressure.
They look fine, feel good and the car handles perfectly.

Why do we want ot go up into the 40's???

Ok, to elaborate on my February post.....

I've since had new tyres fitted, the last ones lasting 6000 miles. I had an alignment problem which has now been fixed.... -8mm toe, should be +1mm.

I've also pumped my tyres up to 40 front and 36 rear, due to the rubber completely disappearing from the inner edge, and the outer edge not far behind at 32 front 30 rear..
I now have Falkens fitted, I'll update here if theres any probs.