Tire Pressure

I just increased mine to 40/38. Haven't gone far since but they seem to have better rolling ability at that pressure BUT I thought I read 42 psi max on the side of mine. They are P195/55/R16 I think. Bridgestone Turanza EL400 86V. I must look again but it's hard to read. Maybe I read it wrong? I've been reading as many of the posts regarding tires/pressures/LRR/handling as I can but the more I read the more confusing it gets. My concern will be more in the winter than now regarding handling higher inflated tires goes. Read the LRR chart posted but most posts talk about the 15" tires. The 16" definitely handle better (our other Prius is a 2003 Classic Sedan which tends to make me oversteer at higher speeds)

 

<div class='quotetop'>QUOTE(kcoruol @ May 25 2007, 02:35 PM) [snapback]450071[/snapback]</div>

Well, most on PC have been running 42/40, and I had been doing that on my original Integrities.

I just put on new tires on Wed. that are rated at 51 psi. If I don't get negative feedback on the advisability, I may up mine to 46/44 in a few days. Anyone else have comments on this?

Dave M.

 

Hi kcoruol

In my 2004 Prius (traded for a 2007 Touring last November), I ran the Integreties at 40/38 psi.

I tried the same tire pressures when I got my 2007 Touring and didn't like the 'feel' of the ride. Must be the firmer suspension combined with the higher than Toyota-recommended tire pressures. After a few days, I lowered the tire pressures to 36/34 psi, just a couple of pounds over the recommended. I liked the feel and ride much better notwithstanding some reduction of MPG.

My 2¢ worth.

 

When I got my Prius home from the dealer I checked the psi on my tires and they were already at 42/40 which seems to be the optimal range on the PC boards.

 

<div class='quotetop'>QUOTE(kdk84 @ May 26 2007, 04:13 PM) [snapback]450541[/snapback]</div>

I have mine at 50 psi frt and 48 rear. I've been reading quite a bit about differing opinions on tire pressures and I think tomorrow I'll let a little air out and drop it down to something more sensible. 48/46 ought to do it...MPG is 50.4 with 500 miles on the Prius.

 

<div class='quotetop'>QUOTE(kcoruol @ May 25 2007, 04:35 PM) [snapback]450071[/snapback]</div>

I am going with 38/36 to get a more compliant ride. Tried 42/40 and got a lot of thumping on our winter ravaged roads (potholes). I even lowered it to 36/34 in winter for traction and ride compliance tho you are unlikely to ever see Minn temps.

 

<div class='quotetop'>QUOTE(dmckinstry @ May 25 2007, 10:05 PM) [snapback]450201[/snapback]</div>

If the sidewall max is 51 then start at 51/49 for a few weeks, won't hurt a thing. And when that's OK then we can talk about really going to a hypermiler pressure.

What tires and size did you get?

Wayne

 

I've got it at 45F/43R and it drives and handles very nice.

 

<div class='quotetop'>QUOTE(FireEngineer @ May 29 2007, 10:44 AM) [snapback]451542[/snapback]</div>

I got the Toyo Tourevo (LS, I think). I'm pretty certain (I don't have the car or paperwork with me) that the size is 195/60/15. Even though the aspect ratio is lower, the larger width gives close to the same diameter.
I got that brand, since Les Schwab has them locally, and I like dealing with them.

I drove to Olympia this weekend (with tires at 42/40) and averaged 52.0 mpg.
I pumped up to 46/44, when I was in Olympia. The pressure had dropped from the 42/40 I had on them, but the elevation is lower by about 2400 ft in Olympia than Cheney, so gauge pressure will be lower. However, not as much as the drop in pressure. I haven't checked the pressure since I got back. The mileage coming home was 48.8 mpg, but I did have 3 people (one a child) and luggage on the way home. I was using cruise control at 65 most of the way. My legs get too cramped keeping my foot on the gas pedal through that distance.

Just how much difference (%) does one expect in mileage by increasing the pressure beyond the 42/40?

Dave M.

 

<div class='quotetop'>QUOTE(dmckinstry @ May 29 2007, 03:01 PM) [snapback]451629[/snapback]</div>

The % difference depends on the tire and the driving style, just as it does from 35/33 to 42/40. MPG does go up until you reach 60-65 PSI at which point any increase is VERY small and not worth the extra pressure. Everyone you see on PriusChat you see getting big MPG; VABeachPrius, JimboK, myself all run higher than 50 psi.

Wayne

 

<div class='quotetop'>QUOTE(FireEngineer @ May 30 2007, 08:56 AM) [snapback]452103[/snapback]</div>

OK. I think I'll up it to 51/49 when I get home this afternoon. I suspect the mileage won't be a lot over that for 46/44 but should help some. Besides, I'm going into Spokane this afternoon and taking back roads where I don't have to go 65-70 mph. I always get better mileage that way than on road trips (where I don't want to travel below 65), and around town, where the Prius never gets warmed up enough.

Dave M.