[john70t]

Drove a Prius last week. Flat roads were good with warm temperatures. Easy driving. Consistent conditions.

The dashboard said the milage was 43mpg.
Too low.

Since the front tires felt like they were dragging in turns, I checked the tires. They are rated for a maximum inflation of 44psi.

They read 36/36 front and 36/40 rear.
I filled them all to 41-42psi. Never mind the door sticker.
The car felt like it drove "normally" after that.

The milage immediately went to 50mpg.
The next day, the milage went to 55mpg.
Curiously, my leadfoot girlfriend got 55mpg as well.

Although the computer calculates the milage in 1/10ths of a gallon, I have some suspicion of its accuracy, but was suprised at a dramatic 12mpg change from changing tire pressure 4psi.

Could high-pressure, harder compound tires be part of the key to reducing national fuel consumption?