Tire pressure upgrade results

Yes, It worked for me also. I went from 50.5 to 56 MPG.
This summer I am doing 60-61. I just do the speed limit, no more.
:second:

 

Raising the tire pressure has a direct effect on the individual tire contact patch. For example, in car racing, tire temperature is taken accross the tire surface; inside, center and outside. The temperature should be even between the inside, center and outside. To alter the temperature readings, you can adjust ride height, camber settings and tire pressure. The car should also be weight scaled front/back/left/right for optimal performance.

Here are my touring Prius settings, at stock ride height, using Longacre camber/caster guage;
1.75 degrees camber with 1.5 degrees caster

Here is an example of the optimal tire temperature readings, (not actual temperatures);
Inside Center Outside
225 225 225

When you raise the air pressure, tire temperature would look like the following;
Inside Center Outside
180 250 175

I would bet your tire wear will also show more wear in the center, as compared with the inner/outer areas of the tires.

Can anyone confirm that raising tire pressures will not lead to shorter tire life?

 

It's been confirmed many times in other threads. One with pics

I believe Bob did temp. measurements also.

 

Hi Sheepdog,

Not surprised by your jump in mileage. But I am surprised by your not noticing any difference in ride. For me, the difference in ride and handling was dramatic. But I could have been imagining things.

 

I think you would lose that bet. These are belted radials after all.

Many on this forum including myself have not experienced increased center wear. We have noticed reduced inner/outer wear over factory recommended pressures when running 42/40.

I have heard of no reports of increased tire wear related to 42/40 pressures.

 

Nope, I now have 60,000 miles on my HydroEdge tires, and I have run a range of 38-42 PSI the whole time, with 42/40 right now. I don't think the higher pressure has hurt much, as the wear is pretty even on my tires. I might replace the tires before snow season (Dec-Mar), at around 70K miles on them, because the tread will be a bit low at that point.

I got 65,000 miles out of the OEM tires running 36-40 PSI usually. I think alignment affects wear more than the increased pressure.

 

As I commented, increased tire pressure will lead to tire wear showing in the center of the tire, with less wear showing in the inner/outer sections of the tire.

Even though there may be no evidence that running increase tire pressure does not reduce the expected life of the tire, I will conservatively continue to use adequate air pressure to maintain even tire wear.

I hope everyone practices lowering their air pressures when the weather gets wet or cold, to reduce your chances to hydroplane/slide in rain and snow. Unless someone wants to share their story about traction control while running higher air pressures.

 

Ok so let me get this straight. You are saying that despite all available evidence that is displayed in here by various members that runs contrary to your opinion you still stand by it?

Can you please explain why I am not seeing increased wear despite 50psi+ in my stock tires? I am curious why my situation does not fit your predicted outcome.

I'm hoping you have a real reason backed by physics and not a Crabtree's Bludgeon type response like we had in an earlier thread. lol

In case anyone missed my link I will post the pictures of my tires after over 30k miles of high pressure.

 

F8L, I thought you were even running as high as 60lbs over the past half year (maybe you didn't want to freak them out ). But yea, people NEED to get away from the 36lbs nonsense. Here's what 36lbs has done for more than one PC member, as to treadwear:

http://techno-fandom.org/~hobbit/cars/tpms/treadwear.jpg


And F8L, how can you only do 300 - 400 miles if your tires are pumped that high?

Shouldn't it be more like this?

 

I have been running over 60psi since about January or so I believe. I'm currently at 66/64psi. I do not feel I have accumulated enough miles to determine wear patterns though so I stated that I've been over 50psi because I have been running over that for quite some time now.

As for the milage per tank. For some reason even at 62mpg I can barely squeeze out 500 miles to a tank and that is getting down to 1 pip which I never do. On average I can never get more than 9 gallons in the tank so that limits me. My usual fillups are in the 7-8 gallon range if I let the tank drop low. I normally fill up around 2-3 pips (380-450miles). I've read in a few places where the 2004-2005 cars tend to get less overall miles per tank. Whether that is true or not I seem demonstrative of this idea.

 

I went from the stock numbers (33/35) to 40/38. The handling got pretty twitchy at highway speeds, and in cross winds with this set-up. I've now notched it down to 38/36, and most of the problem has gone away.

... Brad

 

i'm running a little over 42/40 and everything seems fine, i've driven in the city, 80+ on the freeway, directly into headwinds and the sort and i've noticed no ill effects on handeling. the ride is a bit bumpier (but nothing bad at all) so thats the only "downside"

 

This has been my experience as well. No matter what I do I get the "freeway wander". lol

 

Just out of curiosity, why do you bother with the 2 PSI differential when you're going that high? I can't imagine it makes a difference. I recently bumped mine up to 50 all around (had been at 42/40). It occurred to me that really is no reason to the keep the front slightly higher than the rear when they are so hard. I guess I could see the purpose when they are squishy in the mid 30s.

I'm getting a new set of Pirelli P4's installed tomorrow and will ask the shop to put them at 44 each. Don't want to freak them all about going over the max PSI. I figure I'll run keep them like that for a few days just to get a feel for the new tires and then bump them up to 50 assuming there are no problems.

 

Prius tire pressure dogmatic law? lol

Honestly I never thought about it. I just did it. Let me know how the new tires work out for you. I know you are pretty good about tracking milage so I'm eager to see your results.

 

Time to free yourself from the shackles of the 2 PSI nazis!

I will let you know. We are leaving for vacation right after I get the new tires. But the first place we're heading is only about 100 mi away and I have made that trip frequently. That's part of the reason I'm keeping them at 44; to compare to previous trips. I'm sure I'll take a hit ... going up to 195/60/15 as well.

Then we're heading another 400 miles or so a few days later. I'll bump them up to 50 for that one I think. I'll report back in a couple of weeks after returning from the trip.

 

This has always been the long held theory on tire pressures and tire safety. However, I recently boosted my presures to 50 and then 55 and produced increased MPG. Also am monitoring my tire wear with a depth guage. Without, actually measuring and converting I'm quite sure my guage measures millimeters. Interestingly after faithfully filling to bead pressure (40-44lbs) for the last 30000 miles on replacement tires. The side treads had 6-7mm tread left and the middle tread had 8mm, indicating LOW tire pressures, even tho these are easily 10 lbs over recommended pressures.Since filling to 55 lbs the tires are also running cooler. (to the touch) So my experience has been totally contrary to the expert advice given to consumers over the years. I agree with F8L, I'm not sure that I have the guts to put 70 lbs in, yet...............