Re: Increase mpg. Undertray?
An underplate definitely improves MPG, but the whole aerodynamics of the vehicle need to be designed in concert with it. I don't think just adding one is going to help you.
2015 Lexus LS460 AWD, Nebula Grey w/Light Grey Shimamoku Interior
2015 Kia Sedona SX-L, BlackBerry w/ Dark Burgundy Interior
Previous Jeeps: 2014 Grand Cherokee Overland; 2011 Grand Cherokee Laredo X