Tire Pressure Poll - Where is Yours?

[philmcneal]

[quote=msirach @ Jun 8 2007, 02:54 AM) [snapback]457921[/snapback]</div>

I'm driving the Prius to work for the first time today. I raised the pressure to 60psi in each tire. I'm driving the same route that I routinely get 75 to 90 mpg in the Insight.
[/b]

represent!!! 55 psi and 53 psi for the rears, i'd love to go 60 but the last time I went 60 my tires had more bumps than usual (diff car though civic), if your road or daily commute consists of roads smooth as in BUMP FREE then i wouldn't hesitate at all to bring them up to 60's but since I got pothole/bumpy hell in my area, mid 50's psi is good enough for me.

Tires like a ROCK is awesome for coasting, and makes good difference when cruising on the freeway at lowest efficent rpm band as possible.

Also for those worried about blow ups, just remember it takes MUCH MUCH MUCH MUCH LONGER for a HARD TIRE TO WARM UP rather than a soft tire like 30 psi. The rolling resistance is so little with hard tires its hard to create heat within the tires, plus with the aid of regen I don't think these tires are going through a tough time as opposed to someone racing to the red light and slamming on their brakes. I've gone 15 miles and still had the same psi reading when I checked them cold (yes i have a digital gauge that measures by the decimals.... only tools would trust their tires to analog gauges...)

But hey, if you just want a good comfort of ride quality and decent mpg MID 40 psi works well for most prius owners, but if your hardcore like me and want the 60 mpg tanks (or 70 mpg tanks VABEACH YOU LUCKY]!#$#@!) then pump them up LIKE A ROCK and coast till there's no tommorow!

If your that paranoid, just don't do it, simple as that. But if your willing to learn, open and share you'd be surprised what hard tires can offer an individual.

Good luck folks, for the sake of high psi folks like me don't over do it! and ASK QUESTIONS IF NOT SURE ABOUT HIGH PSI.

[dmckinstry]

<div class='quotetop'>QUOTE(dmckinstry @ May 31 2007, 11:31 AM) [snapback]452717[/snapback]</div>

It's still to early to say. I understand new tires need to be "broken in" some, and the driving is never consistent enough (my wife drives the car too) to be certain how much difference any one change makes during a short while.

The next time I could make any real tests is the next time my wife takes a trip for a week or two. That could be nearly a year.

Dave M.
[/b]

I'll give an update. I was quite discouraged with my mileage. It dropped to about 50 mpg, including some slow driving, but not nearly as much as before. However, I discovered a few days ago that the dealer had dropped the tire pressure to about 40 psi at my last oil change a little over a week ago. That's in spite of the fact that I told the service manager that the tires were new and I had the pressure where I wanted it. I think he made a note on the service slip, but I guess the tech didn't notice that. I suspect the oil changes go through a sequence, including them adjusting tire pressure, even before it gets to the tech that does the change.

I won't know much until after I make my next fillup.


Dave M.

[Lola'05]

I have had Lola's at 40/38 from the get go...that is soon coming up on three years. Average is 53 to 57 mpg, except during the lowest temps in the winter. I will not accept going without the heater then. Some things are a trade off.

I have been very happy with her. The higher the price of gas goes, the happier I am.

[TennPrius]

I've been running 65psi for awhile now. Higher before that but i cant take the really harsh ride. You can fill every flaw in the road.

[chrisspaulding]

.
52f/50r
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[Doc Willie]

I was driving 40/42, but went up to 50 for the Green Grand Prix. Since the ride and handling we quite tolerable, I have bumped up to 42/44.

[PriusSport]

I'm at 38/36 psi, and just got in after a thunderstorm. The Integritys grip and stop just fine in the rain. mpg averaging 51.6 in suburban driving. Some short trips.

[benw123]

I boosted mine at the weekend to 36/38 from 35 all round. Already the ride is a touch harder so I think I'll hold steady at this for now, particularly as the quality of roads in Britain are generally so poor.Normally I see around 62-63mpg (or 51-52 mpg in US gallons) on my commute into London and today I saw 63.7 (53) without really trying hard. Best so far was 65.7mpg (54.7) last week which is the official mpg figure in the UK (i.e. hypermiler!).

[Bobwho]

Just below the max sidewall listed pressure. I trust gauges as far as I can throw them and my shoulder is messed up so I cannot throw very far.

[Eug]

Personally, I wouldn't do anything beyond 44 PSI on Integritys since it's beyond the Integrity's maximum specification. Yeah, they'd probably be fine, but I think it's pushing it. However, I do think Toyota's recommended pressures might be a tad low. The unfortunate part is that the dealers may be setting them even lower. The edge wear on my Integrities has been much more significant than the centre wear, but I wonder if part of that is because my dealer has not been setting them at the factory recommended 35/33. See below.

When I got my new Michelin Primacy MXV4s today, the tire shop set them at 32. I asked them why and he said that's at about what they should be set, and he recommended no more than 35. So I thought I'd try it at 32.

At 32 PSI, these Michelins felt like mush, and even more so than my Integritys. I didn't like the very soft handling. I just so happened to be going directly to the dealer to get an oil change so I asked the dealer to set the pressures at Toyota's specs. When they were done, I asked them what pressure and the Toyota mechanic said they kept them at 32 like they should be. I told him that I'd like them set at 35 front and 33 rear (like the manual advises), but the mechanic specifically told me not to have different front and rear pressures. Anyways, I then said fine, but told him to raise them to 35. So now all four are at 35. With just the 3 PSI change, handling is noticeably better. I'll do a bit of driving on them at 35 but I suspect I might push the fronts to 37, and keep the rears at 35. Is there any problem keeping all four pressures the same, given the weight of the engine in front? (Luckily, tire noise is less with the Michelins, so I suspect 37 for the fronts will be perfectly fine for noise.)

BTW, in terms of tire pressure, I don't care about mileage at all, despite owning a Prius. My reason for adjusting pressure is handling vs. comfort. With the PSI at 32, handling is compromised so much that I become uncomfortable, even though it's a soft ride.

P.S. There are some crazies out there. At the tire shop, I saw some tires that had just been replaced. They had so much edge wear that even the steel belt was worn through at the edge.