Nissan Cube Life - Nissan Cube Car Forums banner
1 - 5 of 5 Posts

·
Registered
Joined
·
930 Posts
Discussion Starter · #1 ·
hey guys, I was curious about other cubists who have replaced their OEM wheels for a new set of wheels and tires. I was reading at toyotires.com about replacement tires and read about the tires on my 18' now. It says that the recommended tire pressure for OEM specifications should be 41 PSI, does that sound a bit high? especially if OEM tire pressure is 33 PSI I think.... My tire size is 205/40/18 and the installers at three different shops only inflated my tires to 33 PSI.
 

·
Registered
Joined
·
117 Posts
I'm rolling 38PSI with 205 45/17 I think you need a little higher pressure with lower profile/wider tires. (Especially with pot holes around here in winter time!) :D
 

·
Registered
Joined
·
671 Posts
Strictly speaking, the optimal tire pressure is the one that keeps the entire tread patch on the road. With a wider tire, but the same inflation pressure, it'll take more vehicle weight to maintain proper tread contact (more square inches due to the wider tire). So, if anything, the tire pressure should be less, not more. I'd say stick to the factory recommended pressure as a reasonable compromise :).

PS. Cranking up the inflation will result in poorer traction and accelerated wear at the center of the tire tread. On the other hand, it'll also incrementally increase MPG due to less rolling resistance and vehicle turn drag (thanks to the poorer traction). As always, your choice :)!
 

·
Registered
Joined
·
930 Posts
Discussion Starter · #4 ·
Found my answer and I guess this will help out others for their recommended tire and size.

Apparently low profile tires generally have a higher standard pressure, due to the fact that they take more load on a smaller sidewall and also depends on the tread surface area or width. So the tire series I have are 205/40/18 and toyo's recommended tire pressure is 41 psi about 4 less than max psi. If I went with a 215/40/18 the tire pressure would be less because of the increase in width of the tire. If I went with a 205/45/18 the tire pressure would also be less. A 215/35/18 requires a high pressure because of the really low profile. I have also found out on a Mercedes-Benz forum that the tire pressure recommendations change as you get the optional plus size wheels from the manufacturer.

So anyone who is running 17, 18, 19 inch rims should not follow the recommened tire pressure found on your car, but rather what is recommended by the tire manufacturer. Not all manufacturers are going to be the same.
 

·
Registered
Joined
·
671 Posts
So what you're saying is the less the side wall height, the greater the pressure to offset the reduction of vertical cushioning (ie. reduce the risk of bottoming the tire). However, given the tire patch also increases with the wider tire, you can also expect the tread wear to increase and be center tread focused. An interesting situation. I guess only tire life will tell the tale :)!
 
1 - 5 of 5 Posts
Top