Rolls Eyes... No....that is NOT a contradiction..... Admission that ALL OF US cannot pick a PSI and set it...and have it stay perfectly at that PSI because of atmospheric realtities...is not a contradiction to the concept of either choosing to try to inflate to the recommended PSI or choosing to inflate at personally chosen level are choices we make as owners. I kind of took for granted that EVERYONE KNOWS by default that air and expansion and contraction of air molecules will be affected by atmospheric conditions. And this happens at whatever PSI you pick. Choosing a inflation approach...is a choice. Atmospheric changes affecting that choice....an inevitability... Two separate realities...not two contradicting ideas.
You nailed it... you think (operative) that we are wrong, when, even if repetitively anecdotally, our experience suggests we are operating our vehicles in a perfectly valid manner. I like to look at it as a energy efficiency - personal comfort continum, where some of us like to trade of as much comfort as we can for FE. Miserly use of climate controls, rock hard tires, tending to grill blocks, longer times to destinations all gladly endured to tease out a few extra percent mpg...hardcore, badge of honor, at its worst jerky moral high ground stuff. At the other end of the spectrum is ironically interior climate constantly controlled, even preheating - precooling to avoid discomfort, tires at placard or below, mash the accelerator to get there now... resource indulgent 21st century is there a pill for that culture. I'd hope most thoughtful people would find their way to some place in between with more of us nut jobs on the far FE end than the other, but I'm afraid the converse is true.
So basically they are saying that those small deviations are OK as they are really unavoidable. And since couple of psi under the recommendation is more dangerous than couple of psi over wouldn’t it make sense to keep them at a bit more than recommended pressure? Upping the pressure will give you better MPG, longer thread life, and sharper handling. Lowering the pressure will only increase comfort and maybe very slightly the life of suspension components. But better MPG, longer thread life, and sharper handling are facts. My tires are wearing evenly on my Prius and they did wear evenly on my older cars too all running above recommended pressures. Of course if I ever saw negative effects of higher tire pressure that would outweigh the positive effects I would lower the pressure.
Happy new year to all and thought I would just speak out loud. Not complaining or arguing or contradicting anyone.. just my truly tested results. at least in South NJ... went and got my oil changed @ 70k miles and they changed my pressure again to 32psi. I left it for 3 tanks (didnt fuelly it because i dont care bout that anymore)... I got 44, 46, 47mpg (not in that order) and temp was about the same anywhere from 42F - 48F today @43F I filled up and decided to air up (to 43psi). Well I am now back to 59.2mpg today on my commute. The car is used for the same commute and not much else as we drive the wifes new JKU everywhere else locally. so for me I have tested/shown to myself that it makes a difference and so far @70k miles dealership said the car is in great shape and solid... as I asked them how all suspension is holding up with the NJ roads... {/talking out loud}
So you let your tires stay under-inflated and you got low MPG. No surprises there. Oh wait, you have a Gen III, so not really relevant to a discussion debating Gen II tire pressures.
Fact: if you have the correct tires for your prius this is the correct psi for the tires. Anything lower will decrease mfg and put poor wear on the tires. When I purchased my 08' this was my issue with getting bad fuel economy. Michelin tires low psi. CHANGED THAT DEAL! Haha Bought the correct Hybrid tires= Premier tires and PSI 42. Thanks to Les Schwab knowledge on Toyota recommendations. Posted via the PriusChat mobile app.
Hybrid tires ... You might wanna shop around as I have never heard of hybrid tires. The tires that should be fitted for the Prius are what are called low rolling resistance tires. They maximize the fuel economy of the car.