Went from 32mpg combined to 37mpg (changed from "normal" driving to mild hypermiling)

[why?]

turning the engine off at red lights is only a strange thing in the US. Europe and Japan it is what everyone does, because it saves fuel.

Oh, and gutting the car is more for fun and handling than gas mileage. You simply don't have the ability to take enough weight out of the Yaris to make a significant difference over learning to drive better.

It would be different if there are 600 lbs or more to take out, but even Jason's Yaris is 1800lbs stripped. From what I gathered, removing the rear seats and everything behind only takes out a little over 100lbs.