Optimal Tire pressure Prius 2010

I've owned by 2010 Prius V with 17" tires for about 2 months now. I'm curious what tire pressure other people are using. The specs say 33 psi for front and 32 psi for rear. The tires are max rated @ 51 psi.

I'm averaging about 50 mpg based upon the car but my figures show it can be 2-3 mpg lower. I did a road test driving in the 75+ mph with 3 people and luggage and got actual mpg around 45 mpg.

 

Or really? Then what is it? Helium? Hydrogen? Mustard gas?

 

Around 42 front/40 rear or 40/38 is popular. I run mine there. They are reasonably comfortable and more pressure than that won't help fuel economy much more.

Real fuel economy typically averages about 5% less than what the computer tells you so you are right in the ballpark.

 

I haven't read every posting in this thread but what about the safety factor of less pressure in the tires? eg: Up here in the frozen north stopping on icy or snow covered streets/roads is a major concern for 6 months of the year. Would not more 'rubber' be in contact with the road if the pressure was at 35psi? Especially if they were 'snows' as I put on religiously every winter?

 

That depends on about a zillion things, but generally if you're not hauling a bunch of people and cargo around you'll probably be fine up to about 40, in normal driving conditions
I always advise non-gearheads and non-hypermilers to just go by the manufacturer recommendations---and this advise is generally poo-poo'd upon by the those previously mentioned enthusiasts.
But hey....that's how I roll.
Your contact patch isn't going to change very much in a Prius, driving in the snow by altering the pressure by a few psi either way. There are about a zillion drivers out there who don't even own a tire pressure gauge, which is why cars are now equipped with TPMS.
You DO want to make sure that your tires are not UNDER inflated, since this can lead to seriously bad things....but really...
This car screams at you for releasing your seat belt before you place it into park, or for putting it into reverse, but it waits until your tire pressure drops below 30 psi (sometimes waaay below) before it illuminates an itty-bitty, quiet little light telling you that it might be a good idea to check your tire pressure.
You really think it's that critical?

 

Unfortunately the TPMS is not active when my 'snows' are on as I chose not to purchase another set of special valves, ($200+) up here!
As far as the beeping when I reverse, I had that disconnected by the dealer as it drove me bonkers every time I left the driveway. Could never understand why it was warning me INSIDE the vehicle when some outside unsuspecting shmuck that wasn't looking wouldn't hear a thing??

Thanks for the input.

 

I did a long trip this past week, of about 1,800 miles. Having upgraded from a III to a IV, I had noticed the mileage about 10% lower on the new IV but the wife was the main driver, so I figured it was driving habits? Had a long highway trip, so I switched cars with the wife. Based on what I'd read here (hoping my memory was correct), I put 40 psi all around, and my mileage is now at 56 mpg (compared to 47 mpg prior). So, by adding 10 psi, I got a 10mpg increase, (first 800 miles of trip at 30-32 psi showing 47 mpg average). After an overnight stay, I then filled them to 40 psi, reset trip meter, and 1000 miles more on the same roads for 57 mpg). Sweet! When I filled them to 40 psi, I noticed the steering was much easier, too, in parking lots etc. I will have to ponder a bit, before kicking the pressure higher(you guys running 50 psi are impressive), as the bumps in the road make themselves more obvious with higher pressure.

 

Those are the numbers I use for tire pressure. I like the feel when cornering. I also like the feel of using less fuel.

 

Running 47/49 still give me a good ride.

 

Are all you guys over 44 going over the max PSI on the sidewall?