I want 42/40!

I voted "Other" because I don't know or care what a service person does to my air pressure. The first thing I do when they hand me the fob is adjust it myself, just like I check the oil level before I drive off.

 

I voted other. I adjust my own tire pressure. I currently use 37/35. Until I research it further, I am reluctant to increase the pressure 20% over the recommended 35/33, to 42/40 (but that's another tread).

 

well 36 was way better than the 28 all round when I bought the car. Drove to the nearest gas station pumped to 42F 40R and hit the hiway and 1830Km's later was home. Been 42 40 ever since. On last weeks check they were 41 39 and I pumped to 42 40.

 

I run 40/38. The dealer I use for service has cautioned me both times that it could contribute to tire wear at the center of the tread. However, they set it to what I specify and just make a note on my service order.

WHile I bought my Prius at Toyota 101 in Redwood Cit, CA I get it serviced at Putnam Toyota in Burlingame as a matter of convience (its near a train station). I've been very happy with them.

 

I keep an air guage in the car, and check tyre pressures when I fill up.
On the occasions I have brought the car in for an oil change, I have mentioned that I keep the tyres at 42/40 so that they do not release pressure.

 

Eric, since you normally would be driving the car when you stop to fill up, the tires wouldn't necessarily be cold. How do you adjust for that to get the equivalent of 42/40 cold tire pressure? Is there some formula you use?

 

Hi GreenMachine,

You are right -- I am probably off by a psi or two.
A fellow named Dan Kroushi in Pennsylvania showed that very minimal differences in fuel economy accrue in the 38 - 42 psi range on the Prius stock tyres, so I use 40/38 in the summer and 42/40 in the winter. I have checked tyre pressures at home a couple of times, and never found pressures under 38.

I have seen a calc that corrects for temperature, but cannot remember details -- only that in my local climate range of -10* -- 35 C, it was not a big deal.

If PV = nRT is a fair approximation, and Temp is in Kelvin, a change of 27C degrees would be about a 10% change in pressure.

*addendum -- fixed error

 

My 06 is Staying at 35/33

Maybe it's just an 06 thing, but after driving an 05 TRAC rental for 4 months and 6,900 miles at 40/38 I'm keeping the Integritys at the factory 35/33 settings. The 06 ride is smoother and quieter (although I'm sure it's mostly the new noise/harshness improvements), and I'm at the same 47-48 MPG I was getting with the 40/38 hard riding 05.

 

benighted, how do you have so much time on your hands to go back to mechanics and have them redo air pressure; I hope you are retired. If you are that obsessed then you should be capable of maintaining the psi yourself.

 

The first time I had an oil change I asked to have the tires at 42/40. They told me it would be the right pressure. I found out later that they never did the pressure, but rotated the tires. That meant I had 40/42!

Since then I don't bother to ask and just inflate them the way I want to later on.

 

can you pump tires with a bicycle pump?

 

Yes, you will end up with very strong arms and be able to check off one of your workouts for the week. I suggest only doing one tire a day.

 

In 1985 I bought a small electric air pump. It cost me $90 from Sears. I still have it. it goes up to 80 lbs. of pressure. I use it to put air in all my tires. To me this is an invaluable tool to have in my garage. I don't rely on any tire changer to put what I want in my tires. Much of the time they just blow them up to whatever....

My 2006 Goodyear tires say on the side: Maximum pressure is 45 lbs. Knowing that adjust tires for what feels best for you. I do 42/40 for max. milege.

 

Has anyone done a resonably controlled experiment that proved the benefit of moving from 35/33 to 42/40 or anything in between? Since I'm a very new 06' owner, please bear with me. I found this thread by doing a search so if there is a thread answering my questions please point me to it.
Thx in advance,

 

I have to pay to put air in my tires at the local gas station. I went to several and they all have coin operated air, so even air isn't free. It took me a $1 to finally fill all four tires to my satisfaction, but I don't know how accurate my gauge is, as I heard the pop-out turkey baster style isn't that accurate.

That said and haveing gone through the process I started thinking how the process could be made easier.

Is there anything where you can set what tire pressure you want and the compressor will stop when the tire reaches that pressure? Then I could set the front to 42 and the back to 40 and not have to worry about being over or under or the right side being different than the left. Seems like a simple no brainer kind of invention. So why isn't there one? And if there is...why can't I find one?

For $100 I wouldn't mind buying my own air pump as I can see that thing paying for itself before I get rid of the car.

 

<div class='quotetop'>QUOTE(Godiva @ May 4 2006, 09:29 PM) [snapback]249991[/snapback]</div>

I have one of these: Compressor It fits (barely) in the cargo box in the back and works great. But I also have a quality pressure gauge for when I use shop air somewhere. Using the gauge, I find that the auto shutoff on the compressor is actually pretty close to where you set it. The only problem is, is that the setting dial (gauge) is marked in 5lb increments so I always check it against the more accurate gauge anyway just to be sure.

I bought it at Wally World for less than $50.00.