After his first proper off-road adventure over the weekend Jim The Prius is ready for some aerodynamic testing, first the broken factory undertray needed to come off, it has seen its fair share of mud and rocks and will be replaced by a much sturdier aluminium version, possibly reinforced with a steel frame.
Lots of important things to protect under there, as well as improving airflow to make up for the losses the lift and big wheels/tyres have caused.
Next step is to do a base line test, I've found a flat, straight road that allows me to do 110kmh for multiple hours at a time so I will hold a constant speed for as long as possible while changing various things and recording the average milage from the factory display, windows up/down and mirrors in/out should give me a good baseline before I do front bumper on/off, stay tuned for results!