Pretty much every part of the car and the passengers. Most of the energy that is not absorbed by-, and dissipated through the tires, the suspension and the seat will be transmitted to the driver's only body.
Saw a Prime with OEM 17” rims. Looks good. Not sure I’m willing to give up EV range for looks but we’ll see.
I just use standard 2.2 bar (32 psi) front 2.1 (30 psi) rear and I get fantastic mpg and still get a great ride. That’s on 17inch wheels
You have to realize that anyone driving virtually any Prius can, and will, get fantastic mileage over short distances under certain conditions. This OP did by just driving 135 miles. Cripes! The other day I was getting over 100 mpg for about 15 miles or so. The average for the total trip was about 65 though. You will learn to ignore approximately 97% of what you read on Prius Chat, and by paying attention you will soon learn who makes up that 97%.