Rep Power: 290

what psi should my low profile be at? recently when I bought my new tires, I put them at 40 psi, but for some reason, it seems like its getting less mpg and slower but I do like how it handles. Before I kept it at 30psi and it was softer. is 40 psi too much for our cars?

 
Rep Power: 302

34psi for mine (204/40/17)

the more air, the more stiffness..(but you should be getting alittle more mpg)

 
Rep Power: 347

40's too much!!! 35 max or else ur gonna destroy ur tires

 
Rep Power: 302

No he won't...if you look at your tire It says what the max Psi is.
Mine is rate 50psi max.

35psi is what people normaly set their tires