Why different tire pressure in front and rear tires?

That is what I am concerned about as well. Rght now I have 40 front and 38 rear. When it starts to get warmer, I will drop down to 38 front and 36 rear - then I'll see how fuel economy is affected. I really doubt it though...besides as mentioned by current Prius owners who had driven their Prius last summer stated that they get better mpg than winter.

 

ASSUMING the tire is not physically damaged (like a tear or a bulge in the sidewall), I would not be concerned about blowing out the tire due to the higher pressure.

The tire is certified by the tire manufacturer with the maximum allowable pressure - and stamps that right on the sidewall. For the tire that is on the Prius, it is good to 44 PSIG.

In anticipation of the next question - the rating is for a cold tire. The manufacturer has allowed for the tire getting warmer while you are driving. That's why you measure the pressure in the morning before you drive the car.

Finally, notice the word ASSUMING is in caps.... if the tire is damaged... well, it is up to the G-Ds as to what pressure it would blow at... but certainly if your tire is at 42 psi, it will have a higher chance of letting it rip than if it was at 35 psi.

By the way, one thing for sure: If it blows, the pressure will be exactly ZERO psi !!

There you have - all the choices for you to make.