what should my kumho ast's be at? they are 225/40 on 18x8.9 rims... the sidewall of the tire says max at 50psi but that seems high... im currently riding on the factory rating(that sticker on the door sill) but they feel low going around corners... help please....

 

Chalk line test:

Get a piece of chalk and draw a line across the tread. Drive 50 or 100 yards-Look at the wear pattern on the tire. Center worn with good chalk on the sides= over pressure. Worn sides with good or minimal worn center = under pressure. Even wear across the whole line = right on.

Measure the tire pressure at that point and match the other side to that. Front and rears are usually slightly different- so to do it right- Get one front and one rear. Match them all and reset TPMS as needed....All set!!

I use this on my all terrain and mud terrain set ups for my truck and for my tC...Good luck!

 

cool thanks