I believe I read some people going up to 60 PSI??? Recommended setting is around 40 PSI, I would not personally go above 45-50 PSI. What PSI are you guys using in your tires? Hypermilers, what pressure are you using??? Regards,

 

Fluteman,

I agree that 60 PSI is too much. When you overinflate your tires that much, your tire contact patch is indeed smaller and will result in greater fuel efficiency, HOWEVER, your handling and braking performance declines dramatically, and your tires will wear really fast in the center and you will have to replace them too soon resulting in more watsed petroleum.

The best way to measure proper inflation by doing the chalk/paint test. Put a line across the tire tread. Drive a ways and look at the chalk or paint line. If it is only worn in the center, you are over inflating. If it is worn by the edges, you are underinflating which is the worst condition. If the line wears evenly, you have the proper inflation.

 

This shoots down the helium issue. LOL

 

In summer I routinely run 60 psi in all four tires and have no problems. It does not wear faster in the center, and certainly helps a lot in extending glides in both the Prius and the Insight. The handling is crisper, with the tradeoff being less wet/snow traction which is why i lower the tires in the Prius to 44 psi in winter, and 50 psi in the Insight for only the worst winter conditions. I would be more worried about shoulder wear from underinflation.

We have inflated the Prius' stock Goodyear Integrities to at least 44 psi since day one (one June day in 2004) and for most of the year they are at 50-60 psi. 46,000 miles later and the treadwear is still slightly greater on the edges than in the center.

Since I try to check the tires inflation at every fill, I find no need to use Nitrogen, since it doesn't actually improve mielage, just allow you to ignore your tires longer without consequence.