18" Tyre Pressure

[Mossman]

I have had my 2003 VY now for a month or so i decided to check the tyre pressure on one of the digital tyre gauge only to find out the pressure in my 18 inch wheels (GIII Potenza 235/45/18) was 24psi I never really felt that they was underinflated, so i pumped them up to 38psi all round is that ok for 18" wheels its just that the opinions seem to be divided on here thats all?

 

[bennzy]

i asked works contact they use for there tyres and the guy said put 40 in them

 

[Shounak]

I use 38psi.. But the outsides are wearing, so now I'm using 40 psi..

 

[Erik-the-Red]

235/45/18? that's strange, i thought mine were the correct size and they're 235/40/18

 

[Puggle]

wow the placard on my drivers door says 33 - 36psi depending on speed and load. And my 18's are standard issue.

I've since started going 38 all round, they always look a little underinflated (hard to tell with low profiles huh). Been too scared to go any higher (infantile fear of the tyre exploding in my face...)

Can anyone confirm the safest upper limit? I want to get them higher for better handling, but not so much that they wear in the middle, or blow up in my face.

 

[MaN|aC]

38 psi is fine for 18's, any more higher psi you will feel a rougher ride

 

[naf33n]

usually the recomended max pressure is about 50psi. all tyres say it on the side wall some where but around the 40 mark is good. most people pump theres up a little more on high trips as the car rolls easier and uses less fuel

 

[ashtray1]

i have falkens 235/40/18 and mine say max load is 44psi but the guys at tyrepower said to pump it to 50psi cause the will last longer

 

[vy1sv8]

50 psi :my: , i wouldnt go pumping it anywhere past 42 really as they heat up quite alot when you get going thats all

 

[Conceive This]

I Work for beaurepaires
and i have done plenty of Tyre technology coarses and this is what ive found.

NOTE: First off remember the tyre placcard on the vehicle is factory fitted
this is the comfort level prescribed by the vehicle manufacturer and is not tyre rated

15'' and 16'' pasanger tyres = 30-32psi

17'' Proformance tyres= 32-35psi

18'', 19'' and 20'' Proformance tyres= 34-36psi

work utes and vans pressure set to 40psi

Now of coarse this is only a guide if you feel its a bit sloppy
you are able to increase these measurements

NOTE: NEVER EXCEED MAX TYRE PRESSURE (located on the side of the tyre)
this is usualy but 50psi

Remember more pressure gives you greater steering response tho can stress the tyres integrity, also there is less give if you hit a pot hole this could cause tyre sepperation (sidewall bubbles) or damage your rims..


NOTE: if you are travaling log distances ie. interstate all measurements should be increased by 4psi this also aplies to fully laden vehicles.

With 4WD

all tyre pressures should be set to 40psi depending on your comfort


Now all these measurments should give you maximum life and proformance
from your tyres...

SAFE MOTORING...