Minimum/Maximum tire pressure on 17' wheels

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

 

A Priori: Can you tell us the tire pressure you use on your 17" tires? Thanks.

 

So what is your pressure set at?

 

I've varied it quite a bit across my 4+ months of use.

I started at 38/37 (front/rear), then I gradually moved it up the scale to as high as 48/47. I've dropped it and raised it several times. Presently, I'm running at 45/44. Higher than that the ride not only was a bit too harsh, but I also thought the handling was being affected negatively. Lower than that I've felt the mileage really dropped. I've enjoyed the handling and the ride better at 40 and higher, and I've found the fuel economy to be noticeably better once going above 38.

Hope this helps.

Remember: This is just what I do, and the numbers are adjusted by me based on conditions. Also, these are pressures on the 215/45 R17 tires with max sidewall pressure (cold) of 51psi.

 

What does the drivers side door plaque say for the correct inflation?
Usually these are the best for the suspension etc.

 

I believe the inside door recommendation is for 33/32, but I'd have to confirm by actually going to my car!

If your next question is: Why are you so much higher than the recommended tire pressure, then you'll need to spend some time reading the numerous posts on tire pressure. One that you could read that concerns the 2010 17" wheels is my earlier thread: Tire Pressure for the 215/45 17s -- Here We Go Again!

I had a 2007 Prius, and the wear on the tires at the recommended pressure was too high. Once I bumped the pressure up to 42/40 and, later, 44/42, the wear dropped down, the fuel economy jumped up, and the ride felt better (bumpier, perhaps, but better control).

 

And safety..... See post #12 in http://priuschat.com/forums/gen-iii...ts-best-tire-pressure-fe-safety-handling.html

 

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.

 

33/32

 

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.

 

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

 

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

 

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.

 

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:

http://priuschat.com/forums/gen-ii-...24-integritys-over-35k-miles-50-psi-pics.html

http://priuschat.com/forums/gen-ii-...g/63223-20k-miles-nokian-i3-tires-50-psi.html

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).

 

I have my tire pressure at 51lbs.

 

Welcome to Priuschat.

This is with 15" tires? If I recall correctly 2nd gen also had 16" tires, on the Touring model?

My 2 cents: 51 psi will make for a harsh ride; consider dropping to the pressure shown on the driver's door decal? This is Toyota's recommendation, a balance of various factors.

Assuming you're running higher pressures for better fuel economy: I'd try it for a tank, see what happens to your mpg. It'll likely drop a bit, but maybe not that much.

If that's too much of a drop for you, maybe split the difference, try something like 40 psi.

I've nothing to back it up, but I suspect extremely high pressures make for more wear-and-tear, particularly for suspension components and wheel bearings.