My MPG's have gone up about 2MPG with the addition of NAPA oil pan heater. I plugin at home and at work and I'm averaging 51-52mpg with temps around low 30's. With speeds in the 40-55mph. I currently also have Grill Covers,GasPods and wheel covers on MADMAX. Those with block heaters really got it made by adding Oil Pan Heater, because you can maybe get to the magic 128*F WT and be able to go into EV mode quickly and save more gas. :) Paul