Minimum/Maximum tire pressure on 17' wheels

[hybridprius]

Originally Posted by a priori

All three OEM tire choices for the 17" wheels on US Prius models (2010, that is) have maximum sidewall pressure ratings of 51psi.

Hi a priori,

I checked the sidewall rating on my 17" Michellin OEM tires and it states a max of 44 PSI. But, when I checked the specs online it states 51 PSI. Do you why there is a difference?

Thanks.

[dc202]

Originally Posted by frankblack0503

hey all,
wanna know if my tire pressure is not 2 high on my 17' wheels...
(feels like i'm jumping on the road)
what is the max/min tirepressure for this size of wheels ?

Thanks !

33/32

[tumbleweed]

Originally Posted by hybridprius

Hi a priori,

I checked the sidewall rating on my 17" Michellin OEM tires and it states a max of 44 PSI. But, when I checked the specs online it states 51 PSI. Do you why there is a difference?

Thanks.

My car came with Toyos and they are marked 51 on the sidewall. If I were you I would email all the information on the tires to Michelin and ask them what the deal is.

I just checked the TireRack.com site for OEM Michelins for the Prius V and they show this tire which is 44psi:
Tire Specs for Michelin Pilot HX MXM4
If these are the tires you have I would say the 44 is correct.

BTW they are on sale for $113 ea, a real bargain if someone needed tires.

[David Beale]

I -still- want to see a picture of those 17 foot wheels! (we've seen this typo before).

[ursle]

Originally Posted by Frankblack0503

What is the max/min tirepressure for this size of wheels ?

205/45 17's
running 45-43
door sticker asks for 35 all around
max capacity on side of tire is 1/2 bursting capacity
ymmv

[F8L]

I run my Kumho Ecxsta ASX's at 51psi (sidewall max). I tried runnin 58/56 but I couldn't tell if MPG got any better so I dropped the pressure for a bit more ride comfort. I tend to hit corners pretty hot so I like having well inflated tires.

[elkhornsun]

The maximum pressure shown on the side of the tire is for safe operation of the tire which will be mounted on different cars with different gross vehicle specs. Toyota gives a recommended pressure for the stock tires on the Prius that is going to be safe for any tire you put on the car. As with the Bridgestone & Ford Explorer problems an under inflated tire is more dangerous and likely to experience a catastrophic failure so it is better to err on the side of too much air where the only downside is likely to be reduced tire life and increased slippage while cornering.

Higher pressures will provide high mpg but that should not be your only concern. Having an accident due to increased breaking distance or control of the car is going to quickly eliminate any savings accrued from the higher gas mileage. If I get 10% better mileage with my Prius my fuel cost savings at 12,000 miles a year (even in California with the highest prices in the nation by far) would be $80 a year of about 22 cents a day - hardly worth shortening the tread life of the tires or chancing the safety of me and my passengers.

With my trucks where 40K was normal and tires are quite expensive compared to most car tires it took a couple sets and experimentation to get the optimum tire and pressure to get the most miles per set of tires. I have gotten even wear at the Toyota's recommended tire pressures with the OEM tires so that will be the starting point for the replacement tires as well. If I lived in a cooler part of the country I could see increasing the pressure during the winter months.

[F8L]

Originally Posted by elkhornsun

The maximum pressure shown on the side of the tire is for safe operation of the tire which will be mounted on different cars with different gross vehicle specs. Toyota gives a recommended pressure for the stock tires on the Prius that is going to be safe for any tire you put on the car. As with the Bridgestone & Ford Explorer problems an under inflated tire is more dangerous and likely to experience a catastrophic failure so it is better to err on the side of too much air where the only downside is likely to be reduced tire life and increased slippage while cornering.

Higher pressures will provide high mpg but that should not be your only concern. Having an accident due to increased breaking distance or control of the car is going to quickly eliminate any savings accrued from the higher gas mileage. If I get 10% better mileage with my Prius my fuel cost savings at 12,000 miles a year (even in California with the highest prices in the nation by far) would be $80 a year of about 22 cents a day - hardly worth shortening the tread life of the tires or chancing the safety of me and my passengers.

With my trucks where 40K was normal and tires are quite expensive compared to most car tires it took a couple sets and experimentation to get the optimum tire and pressure to get the most miles per set of tires. I have gotten even wear at the Toyota's recommended tire pressures with the OEM tires so that will be the starting point for the replacement tires as well. If I lived in a cooler part of the country I could see increasing the pressure during the winter months.

One thing to consider here is that overinflation of the standard tires on a Prius does not decrease tread life and in many cases has actually increased tread life by inducing more even wear. This has been documented by many owners. Here are my experiences:

Integritys with over 35k miles @ 50+psi (pics)

20k miles on Nokian i3 tires at 50+psi

Now compare this to how many owners complain about how quickly their tires wore out while running the recommended tire pressure.

It appears that the very narrow tires (modern tires) do not suffer the same problems we used to see with older designs on wider tires (275/45/17).