What will 42 lb of tire pressure do to my Prius suspension?

<div class='quotetop'>QUOTE(philmcneal @ May 3 2007, 04:36 PM) [snapback]435096[/snapback]</div>

Well, I thank you for the tire-pressure lesson. That's all good to know.

I will say of John, that he's not a hyper-miler, or an extreme driver of any sort. His mission is to demonstrate what the Prius will do if you drive it normally (i.e. as most people drive their cars) and not to show what it's capable of under extreme conditions.

I also note your warning to drive gently and cautiously if I decide to over-inflate, and your characterization of over-inflated tires as having less grip. So, since my goal is safety, rather than high-mpg, I'll stick with 42/40.

Again, thanks for the information.

 

<div class='quotetop'>QUOTE(daniel @ May 6 2007, 04:57 PM) [snapback]436551[/snapback]</div>

i compeltely agree that the average joe driver should stick with 42/40, 30 is just way too "soft" for the kind of weight the prius carries. Economy tires for a mid size hatch weight, since tire guys recommend putting more psi if the weight of the car is increased (with humans or cargo).

And John's site is awesome, heck even I was a victim of not knowing anything about the prius until I scrolled through his fantastic site.

as for the overinflated tires having less grip I'm still on the ball park on that one, i remember on greenhybrid someone posted their tests of stopping distances of different psi. And apparently the distance decreased as psi went up, although the effect greatly demished after going past a certain psi point ( i think it was 55?) so there is a sweet spot for the tires that's for sure!

i'll post the link if anyone's that's curious, although i'd have to dig for it.

although i dream of smooth no bumps roads one day... then i'd go all out on the psi... but no... road conditions are harsh with the cracks and potholes we have today... it seems its harder to make roads smooth these days... Every now and then I have to see new cracks or openings on the daily roads I commute and I still dream about that smooth road where not even a bump is experienced.... well one can dream!

 

I have long advocated that tires should be made of concrete, and roads should be made of rubber. Then nobody would ever get a flat tire. If the road goes flat, that's the government's problem.

 

<div class='quotetop'>QUOTE(philmcneal @ May 6 2007, 03:05 PM) [snapback]436499[/snapback]</div>

Hi All:
Well, I pulled the trigger yesterday and bought 4 new Michelin X-radials from Costco ($340 after the $60 rebate "cash card" arrives with the exorbitant 7.5% sales tax here in California). The Costco tire guys refused to put more than the "recommended" tire pressures in my new tires. I had been keeping 42/40 as recommended ad nauseum in the various posts here on PC, and hated the stock Integrities, which is why I bought the Michelins with only 24k miles on them (they still had a fair amount of tread, but I was tired of the handling and ride on the Integrities). Anyway, the Costco tire guy told me because we live here in the desert (with Summer temps as high as the 120's) I should never fill my tires above the recommended pressures, as with higher temps the tires will get above the max psi (44). Is this true? When I bring my Prius to the dealer every 5k miles for its service (including tire rotation), I always tell them to fill to 42/40, and they don't flinch. Who is right? Does anyone know what the "best" pressures for the Michelin X-radials in high temp, no rain or snow conditions? My commute is 107 miles each way all freeway (with a very long hill at the end) nd I have been averaging 44 MPG on the Integrities (never could get better than this, although I do drive average 75 mph due to the long commute). Any response from someone more knowledgable than I am would be greatly appreciated!

 

<div class='quotetop'>QUOTE(RonPS @ May 10 2007, 07:48 AM) [snapback]439070[/snapback]</div>

From all the above posts, it sounds like the "best" pressure depends on your personal preferences. Comfort vs economy, how agressively you drive, etc. Toyota feels the "best" pressure is 35/33. John1701a feels it is 42/40. A few posters above feel it's considerably higher. Read the whole thread, especially the posts about how to drive on over-inflated tires. I go by John's suggestions, because on all things Prius, he seems extremely knowledgeable and thorough.

 

<div class='quotetop'>QUOTE(daniel @ May 10 2007, 11:46 AM) [snapback]439326[/snapback]</div>

Thanks Daniel,
I have read all the posts, and I think I'll stick with the 42/40 like I had on my Integrities. The Michelin's are too new for me to know how much better they are (I hope) since I haven't driven my usual commute since I got them, but I'm driving to Las Vegas tomorrow, and then I'll have a good idea about how they handle and feel. Thanks again for the info
Ron

 

The thread is old and has wondered off its original subject which I would like to get some answers. Let's say I run the tire pressure at 44/42 as opposed to Toyota's spec of 35/33. Do I wear out my suspension components sooner? If so how much sooner? (For example, say, I would need to replace the ball joint at 100K as opposed to 200K miles.) Please comment. Thanks!

 

I have consistently run pressures in the 50's and near 60psi. My car has around 90,000 miles on it and, knock on wood, no issues whatsoever with the suspension. Considering the condition of the road surfaces here in WV and Northern VT, where the car has done most of its driving, I consider this a success.

 

I bought my 2006 w/33K I just had it inspected here in NY and if anything was worn they would have found it. I have been running 44/42 on the same set of tires now for over 70K (walmart installed bridgstones) No issues with the suspension but yes you do get more cab noise and it is bumpier. the car now has 110K riders the same as day one on the new tires even in the snow.

 

I've been running 50 48 for 2 years in rural Vermont. No problems whatsoever. Tires are lasting forever. Very even wear - very little wear. Traction is fine, dry wet and snow.