Tire PRESSURE

That's a good call, and that's what I did also. I'm now at 38/36, and pretty happy. I may go down 1 more psi just to see if I notice the difference.

... Brad

 

That is almost certainly not related to tire pressure. Softer for a better ride is a tradeoff for efficiency.

Those hypermilers who recommend PSI beyond the maximum have proven the improvement. And our data shows at the maximum offers a benefit, just not as much.

I suggest collecting more data. It takes a few tanks before you truly get a feel for MPG, due to the many other influencing factors at play.

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The higher the tire pressure, the lower the rolling resistance. Like everything, there is a point of diminishing returns, but the resistance should not increase. Maybe your fuel blend changed?

 

42/40 is what I have used for a while now. usually sitting around 50mpg at lowest end and around 53-55 avg high end. I drive 90% highway at 60-65mph.

 

I worked in a tire store as a youth and learned to always run my tires at their maximum pressure for tire wear purposes. I suppose that I have gotten used to the harsher ride associated with "hard" tires. My touring model allows 51 PSI - and I take it up to the max. I am averaging 56 MPG and think that the tire pressure helps me to some degree. Plus the tire wear advantage.

 

On somewhat related topic. My original tires were under inflated when delivery (33/32) Now I have 38/36, not sure if there any improvements on MPG yet. But I do notice the control of the car is slightly different (esp on rainy day!)

It could be the lower rolling resistance, I found Prius handling is not as good as the cars I have driven before. Not sure how to describe, but it seems more sensitive or maybe I should say it is less wanted to stay on the road.

I am just a bit worry during winter... Not sure how's the handling is like...

 

If you aren't happy with the car's performance then lower the tp. I'm not going above 45 on the Integrities because I'm not fond of the handling.

 

I like the many others here run at 48/46 year round and I think my worst tank has been 55MPG since upping the tire pressure.

 

Your records are fantastic! I'm up here North of Chicago as well and am just getting ready to change Oil and Rotate tires today as I'm at just a hair under 10k (95xx miles) and want to get it taken care of while first off it's nice out and second I'll have it out of the way.

Keep up the great record keeping.

Just for the record, I keep my tire pressure at 48/46 and have been averaging 55-63 MPG.

 

I am a newbie, as of May 1st. Just purchased a 2009 that supposedly was special order, but the person didn't purchase. Instead of the standard 15 inch alloy wheels and tires, it came with 17 inch EFPC wheels with Pirelli tires. I like the look, but after reading a few posts since Friday, I feel uneasy. Anyone have much experience with these specific tires? What is the best pressure?

I replaced a 2000 Honda Odessey with 211,313 miles with the Prius, and so far have enjoyed the "big" feel of the car, but am anxious to learn the best way to get longevity.

Thanks for feedback.

 

Depending on the model they could be great tires. Perreli's usually are and they are usually expensive to boot. Don't expect to get the same milage that people with stock Prius tires and rims get though.

 

Can I overinflate the pressure on any kind of tire? We've been running Blizzaks this winter and were ready to put on the non-winter tires, but looked at the tread. We decided that we didn't want to start next winter with the current tread and plan to just keep them on through this season. Our experience is that they do extremely well holding the road in any circumstances. I do seem to drift a little in dry weather, but I thought it was just me.
The bottom line is: can I overinflate the Blizzaks?

 

I don't think you'll find anyone here who will advise or recommend that you overinflate any tire. Most will recommend going above the Toyota recommended pressure for the OEM tires, but that doesn't mean exceeding the max pressure listed on the sidewalk (44 psi for the OEM Integrities). Check to see the max pressure for your tires (cold) and don't exceed that pressure!

 

OH! I didn't realize the maximum pressure is actually listed on the tire... so much to learn.
Thanks

 

If you have the Blizzak WS-60 in the 185/65 R15 size, then you also have a tire with a max cold pressure rating of 44 psi. If you treat this tire the same way others have handled the OEM Goodyear Integreties, you could try to hold the pressure at 42 front and 40 rear.

 

40/38 seems to be the sweet spot for comfort and improvement in mpg. I tried ridding the donuts on 45/43 a while back. forget it the ride was just to harsh for the small amount of mpg gain.

some people have run over 50 psi on the goodyears, they are true masochist..that is just to ruff of a ride.