Concern about tiers on 2010 V and MPG

One thing I learned when my father was a Goodyear dealer ... never, repeat, never raise your cold tire pressure above the maximim listed on the tires.

My Brigestone tires on my 2010 V are rated for 51 PSI and I run mine at 46/44. They are also rated for 149 MPH which is a little bit faster than the V is capable of.

 

I am one of the people whose posts you've read regarding pressure in the Prius V 17" tires. I was under the mistaken impression that all OEM tires on the Priux V were rated at max cold pressure of 51psi. I've set my pressures above and below your 42/40, and I've told people I am now running at 45/44, but I have not advocated going higher. I've suggested people inflate above the 33/32 number (on the higher-rated tires, as I then understood it), but I am not going to recommend or suggest using pressures near, at or above the max sidewall pressures.

I would not exceed the tire manufacturer's sidewall statements. (Remember, those are cold pressure readings.)

I wouldn't go above the tire manufacturer's sidewall rating. I know some people have, even though they clearly say they don't recommend it. I'm not recommending it, because I won't do it. I won't do it, because I believe it unnecessarily increases the risk of tire failure or poor performance.

 

I, like A Priori, am one of the ones you've probably read posts on about tire pressures.

I am also like you, in that I have a V with Michelin Pilots. The Michelin's sidewall is significantly stiffer than that of the Bridgestone's, thus the lower maximum Cold Tire pressure. And, once again, the Michelin's are VERY sensitive to increases and decreases in tire pressures.

You must take into account, tires are responsible for other factors other than MPGs. You also MUST take into consideration things like: comfort, handling and brakeing.

With Michelin Pilots, tire pressures of 37 Front and 36 Rear give a compromise between those factors, Pressures below 37/36, but above 33/32 will give a more comfortable ride and better brakeing, but at the expense of MPGs. Pressures above 37/36 will possibly produce increased MPGs, but you will give up an important BRAKEING component.

Maximum MPGs may not be worth the costs of a comfortable ride, compliant handling and SAFE brakeing.

Experiment with your pressures, try the factory recommended 33/32, then increase them by a couple of lbs. and see what YOU think/like. REMEMBER, Michelins are EXTREMELY sensitive to small pressure changes, so go slow, and in small increments.

BTW, once you settle on pressures you're satisfied with, don't forget to Re-Initialize your TPMS (Tire Pressure Monitoring System) to reflect the new higher values (look in your Owners Manual in the Index for Initializing, or do a search on this Forum).

David (aka Blind Guy)

 

I have got the Toyo Proxes A20, and my tire pressure is 35/34 psi. Ride is comfortable and I get between 47-50 MPG. Complitely satisfied

 

NEVER exceed the tire pressure stamped or noted on the side wall of the tire. The other important rule is to follow what pressures that are indicated on the drivers side door.

" tire specifies a max pressure of 44PSI with a warning stating “never inflate above 40PSI” Perhaps that the manufacture is anticipating expansion pressure which increases while driving onhot on the roads and freeways.
You should get the air replaced with NITROGEN. This is will change the handling slightly and will keep the pressure increase to a minimum.

Over inflation will cause poor performance and tread wear. At the correct tire pressure, the tire tread is flat to the surface of the road. If over inflated, I will round out like a doughnut and wear in the center. Michelin uses a baz system that help keep the tire running in the correct shape. It is several bands of material the is applied around the casing in the same direction of the tread. Your tires a "V" rated. There is a lot of high tech designed into the construction. La

 

Replacing one gas with another will do nothing to alter handling. Within the pressure ranges utlized by passenger car tires, and at the temperatures reached within the tires (assuming there isn't gross underinflation), there will be no pressure issues when using something that is 70%+ nitrogen versus 99%+ nitrogen.

The tire tread itself will show the same wear pattern, unless you are running highly, highly uninflated/overinflated tires. The steel belts will help the tread stay flat to the road. The bigger problem is roll-over wear on the edges of the tires. This always happens when the tires are underinflated.

It is very common to find underinflated tires. They look like properly inflated tires, until you see them in motion or study the tread wear.

You would not be able to look at three sets of tires and know which ones were inflated to 22psi, 33psi or 44psi.

 

Ok, I'm grinning on the handling comment, but before I start a belly laugh are you saying oxygen (which is 78% nitrogen) will pressure up more as it is heated than pure nitrogen? I assume your dealer sould you the nitrogen filled tire upgrade?