Best PSI for road trip?

i found 38/36 for comfort as well as good MPG

 

To try for max MPG then I would try something between 50psi and 60psi. I run 62/60 on my car and have done so for the last few months with no uneven wear evident. I have run well over 50psi since I swapped the tires back to stock some months ago. I ran over 40psi for about 20k miles.

I'm not telling you to do this but if it was me then I would run them at something close to 60psi.

I know your planned drive quite well since I go to school in Rocklin, Intern in Auburn and commute from Lincoln to Fairfield twice a week for school. I visit friends in the Bay Area often too. lol

 

Every tire has its max cold pressure printed on the side wall. The OEM tires are rated 44 PSI cold. If you run them higher than that you have no warranty recourse if they should blow out.

 

I use at least 60 psi as well. Last summer I routinely achieved 80+ mpg tanks at up to 1050+ miles. As F8L said, I wouldn't tell you to do this but this is what I do.

While the warranty issue may be true, I have 16K+ on the odometer with no odd wear patterns and have driven in temps near 100F without a flat or blowout. My son works in a tire shop and says it is quite common to use 120 psi when getting a bead to seat. This is even with 35 psi max tires. Different tire manufacturers have done burst tests and the tires didn't fail until pressures north of 300 psi.

Again, I'm not necessarily recommending this practice but this is what I do and my FE numbers show it is successful.

 

60 psi on the tire of a Prius ? You are waiting for trouble to happen.

I hope that you do not get a blowout, F8L. 60 psi is around the range of my bicycle tire. This is definitely not recommended by Toyota and should not be copied by someone else. I am even too scared to pump in 60 psi on my tire fearing that it might blow up in front of my face.

If this practice worked ok for you, that is great. Drive safe.

 

I undertsand the implications yet enough people run similar pressures and have done so over enough miles that I am not over concerned. Thank you for the concern though. I drive pretty slow and take back roads whenever possible. No more freeway racing for me!

I am doubtful that 60psi is anywhere near the burts pressure of the stock Intergritys but one also has to account for hitting bumps and such which could cause uneven pressures within the tire and put a disproportional amount of stress on a particular area. That being said I think the only dangerous part about running high pressures is the reduction in contact patch and thus less "rubber on the road" for emergency manuevers and/or braking.

 

The steel belt in a radial tire will keep the contact patch virtually the same at higher pressures. The only significant change will be the amount of sidewall flex. The older bias ply tire construction would allow the center to bulge thus reducing the contact patch.

Prior to my Prius, I have ran way in excess of 50K miles at 50-60 psi on a variety of cars with some having tires with 35 psi sidewall limits. As I mentioned above, tire shops quite often use pressures of 2X or more of sidewall max pressures on a daily basis to seat the beads without them blowing up in their faces. I guess slightly over inflating a tire could cause it to burst but, I could also be more likely to be injured in a car accident if I drive in areas of higher traffic but I won't stop driving in those areas because of that.