Tire Pressure Question

The pressure you now have is OK.

You could pump them up to 44 front, 42 rear cold pressure,
for better MPG.

If you go with the tire pressure on the door; your MPG will be less.

 

#1 yes inflate up to max on tire side wall if you wish, 2# less in rear tires. Best for mpg
#2 not from the car, use a gauge!
Enjoy your new car! Congrats!!!

 

Yep! As engerysaver said!

 

As far as I know, the only way to read actual pressures is using Toyota's Techstream software (which also requires a proprietary cable). If I recall, the manual references some screens on the head unit that can display tire pressures, but the screens arent actually there.

 

Some other tools should also work, if they can be borrowed from a friend.

After adding a second TPMS vehicle to the household, I finally sprang for some tools to handle seasonal tire changes without having to pay dealers or tire shops for programming. An ATEQ Quikset will program the cars, though I have so far done that only with the other car, not the Prius. It can also retrieve existing programmed IDs out of the car, but cannot read IDs or data directly from the sensors.

For the later, an ATEQ VT 30 will query the sensor by RF through the sidewall, retrieving its ID and data. For my Prius, it does read pressures and temperatures.

Unfortunately, these tools are much too pricey for ordinary drivers maintaining a single car, or not swapping tire-wheel sets twice a year. Drivers maintaining only a Prius should look to the much cheaper mini-VCI and Techstream. But I found no indication that the mini-VCI would work with my other car, hence the step up to ATEQ.

 

You might want to follow the instructions in the manual to set the TPMS in case it wasn't done by the whoever set the tire pressures. Otherwise you won't get a low tire warning until the pressure gets down to around 28 to 30 psi. I'm basing this on how the base model system functions, so if is different in the advanced model, I apologize.

 

That extra 4 lbs might not result in any noticeable increase in mileage but it probably will result in a noticeably harsher ride.

Anything between the "recommendation" and the max. on the sidewall is OK but exceeding the recommendation by much often makes for a worse ride, uneven tire wear and increased strain on the suspension.

If all of that is worth an extra MPG or two to you, then go for it.

 

I ran 44 front and 42 rear for seven years in my 2005 thats 9 pounds difference it does make a big difference! My tires wore evenly across the face of the tires. Yes the ride is a little more harsh, but I did not have any other problems at all. YMMV.

last 27 months with plug-in set up the same way, same results so far.

 

I just didn't bother with extra tpms with our snows, solved that issue. Can remember the guy saying: "so do you want tpms?", while shaking his head...

 

That's what I do, and the ride is reasonable for me. Tread life on OEM tires has easily exceeded 60k miles on my two previous Prius' and gas mileage on those averaged 54.5 over 130k miles. I like to check the psi in the garage before starting out in the morning, at least once a month, preferably twice. I keep a portable air tank so I can adjust the pressure at home. BTW, I make a point of telling anyone servicing my cars to leave the pressures alone, and check on them afterward. Sometimes they try to tell me they are required by law to adjust them to factory specs. If it is written on the work order to not adjust the tire pressures, which I sign, it seems to me they are off the liability hook.

 

So do a majority of PiP owners run 42/40 psi? Maybe we should have a thread with a poll to see what everyone sets them at. I keep meaning to try out different tire pressures, but am slightly concerned about lowering overall life of the tires. I think the dealership adjusted my tires to 34 all around last week (showed 34 on one page, and 32 on another page...). Is there any concern for having the tires wear out faster at hire PSI? I have the Yoko Avid S33's. I'm only at 16k miles now, but I'd like them to last until at least 50 or so.

 

I just got mine back from Toyota for the routine service and they did 32/32. I have them at 40/38 now and I'll see how this goes.

 

I don't think there is any thing to be concerned about regarding tread wear at the 42/40 psi. At some point you would start to wear out the center tread faster at higher pressures as the expanding tire would cause the contact patch to narrow, lifting the edges of the tire off the pavement.
My daughter now has nearly 70k miles on her 2011 Prius OEM tires. I have tried to educate her on the importance of regularly checking the pressures and rotating the tires at 5k intervals. She's 2200 miles away, where I can't check myself, so something must have sunk in. She is waiting on Costco's September sale to replace her tires.

 

I set them just slightly above....maybe like 44/42. That way when they inevitably slowly go down over time (very slowly mind you) then they will be in the sweet spot longer and I don't have to fill them up as much.

 

That's pretty decent for OEM's. What's the longest someone has gone on their OEM's?

 

Historically, Prii have had problems with tires wearing out faster, especially at the edges, at the recommended pressure.

For some regions, that is overly optimistic for the OEM tires.

 

I respectfully dissent. In my experience with Toyotas going back 30 years, the cars where I inflated to recommended pressures had uneven wear at the inner and outer edges. Since my 2004 Gen II, where I inflated to about 4psi less than the maximum (but at least 6psi higher than the recommended), I've not had one tire with similar wear patterns, and in fact got more than 80K miles out of a set of Michelin Harmonys.

But the ride is harsher, I'll give you that. Changed front and rear suspension at 140K miles on my '04, which doesn't seem to suggest the higher pressures stressed it much over recommended pressure.