Originally Posted by mpolli

Is it also impossible to get more than 100 MPG in a Prius? People do it all the time. I can definitely get 40 MPG on the highway under certain conditions. Yes it is US MPG. I have a ScanGuage II which is calibrated and very accurate.

Here is how I do it:

In summer when the air temp is high (>70) the air density is much lower so there is much lower drag. This is why airplanes need longer take off distance in hot weather. So that is the first reason. Next I don't go much faster than 62 average. Next I allow plenty of distance so I NEVER need to touch my brakes. Brakes = dump gas on road. Next I don't use cruise control and I do use pulse and glide on flat areas and down hills. Lots of info about this on the web. It seems counterintuitive but adds quite a bit of MPG. Also I don't use AC and I have the windows up. Lately I can get 40 but just on the highway.