Tire Pressure Poll - Where is Yours?

2008 Prius was always at 55-60lbs, new FEHL is at 55lbs, wife's 2010 is at 50lbs. No noticeable difference in the ride between the set ups (obviously much stiffer than at 35-40), but somewhere between 50 and 55 she crosses a threshold and worries they'll "blow up". Tread life is greatly improved over 35lbs, as slow as I tend to drive handling isn't discernably different.

 

Have mine set at 42 40. 57.7 MPG. Love the MPG but the road noise is noticably louder.
Price aside, What tire (brand) is the quietest, and best at low R/R. If there is such a tire?

 

Ok guys, of all those maxes and psi's. I just want you to picture a scenario. Hot 100 heat, 120 miles of highway. If I start the journey with 40 psi cold tires. How much will it increase after 120 mile trip? I think I would be 43 when I reach the other end. But I'm not sure. Max on my tires is 50. So I don't wanna bust them either.
How much max should I keep for cold pressure?

 

No extra margin needed. They already accounted for expected pressure increase on the hot afternoon highway run when they picked the maximum cold pressure rating.

 

My tires are max rated 51. Tried everything beginning from 51/49 and kept decreasing a little by little. Noticed that higher PSI gave very rough rides. No problem on smooth roads but when I hit a bad spot on the freeway I would get a bad shake and would feel something will break and fall off from car. Did not want to keep continuing this only to find out that the car is breaking apart as it ages. Now at 38/36 I am getting a very smooth ride and between 50 to 51 MPG. I like it!!

 

Liek SWprius08, I dropped my 215/45/17s down from 52/50 psi to 46/44 psi today and I am happier with the pressure a bit lower. My tires are pretty hard and at the max PSI the ride was just too rough. I've ran 50+ psi on these tires since I bought them 6 years ago but I finally gave in and went for a bit more comfort.

 

Someone inflated his tires to some very high pressure (60 or 80 psi? I don't remember) and found there was no increase of the pressure after a long drive. He reasoned that at high pressure there was almost no deflection of the rubber thus very little increase in tire temperature and pressure.

High tire pressure is really addictive once I saw the benefit in fuel economy.

 

When I pumped the tires up to 42/40 our gas mileage jumped from 48-49 mpg to 51+, even with heavy use of A/C in this insanely hot summer. Then my husband took the Prius for an oil change, and they deflated the tires back to the pressures given in the manual. The gas mileage immediately slumped back down to 48-49 (still heavy A/C use). I can't wait to see how high it goes at 42/40 in the fall and winter.

 

When I put my 17's back on today I'll start playing with tire pressure and see how it works for the much wider tires. I'm not sure I can handle to 51psi+ anymore though. The ride gets really stiff and bumpy.

 

I run my tires at 42/40. This has given us a smooth enough ride even on pothole laden Atlanta city streets. I always tell the dealership the pressure I want and I check afterwards. Half of the time they follow my directions and half of the time I have to add pressure. I use a plug in compressor that I always keep in the car for emergencies as well as routine maintenance.