moocatdog said:
...I think the Prius weighs around 2900 lbs. empty.
I just checked my door sticker, and here's what it says:
GVWR: 3795 LB
GAWR: 2335 LB
RR: 2250LB
I've always been under the impression that the first number, GVWR, is the total weight of the car. That's where I get the "two-ton" figure. Please correct me if I have misread something.
The Toyota website lists "curb weight" at 2890 LBS. I cannot explain the discrepancy, but for the tire-discussion, I'll be conservative and assume that the biggest number, GVWR on my door sticker, is the weight of the car.
I also checked the tire numbers. Here they are:
Tire sidewall: 44 PSI Max
Door jamb sticker: 35/33 PSI (front/rear)
Valve Stem labels: 32 PSI
Talk about a "mixed message!" With so many different recommendations being made by so many "engineers" who apparently don't talk to each other very often, I figured that "the truth is probably somewhere in between." So I made a choice of 41.5 PSI Front/40 PSI Rear.
Some of us at my place of work think that the car manufacturer decreases recommended tire pressures not so much for safety reasons, but for ride-softness and marketing reasons. After all, I live in the US, land of big cushy couches, Lincolns, and SUVs.....
Given all of this, I still believe that my choice is a reasonable trade-off between ride quality and mileage. It's also a reasonable compromise in terms of safety, because I'm not "at max", and I don't often drive at warp speeds.
My first post here said that the tires each had less than 30 PSI. After having put more air in them, the difference in ride quality has been negligible for me. However, here's the real eye-opener: For this tank, I'm getting an extra 9 to 11 miles farther on each gallon of gasoline. That's an extra 100-120 miles per tank! I'm not driving any differently; it's just that the car isn't spending so much time and effort fighting tire friction!
I hope somebody with automobile design and/or dealer marketing experience can shed some light on the possibility that dealers and manufacturers decrease tire pressure for ride quality reasons.
Thanks!