With our 2016 Volt our lifetime gas mpg's per Voltstats.net is over 45 mpg with over 16,000 miles total. We use the gas engine quite often to make extended trips to the Portland Oregon area and still have an overall mpg of 153+ mpg. Its pretty easy to achieve 50 mpg on the gas engine when you keep speed below 60 mph or so during warmer weather conditions and 60+ miles in summer on pure electric is the norm. Currently our electric range is 63 miles. Last trip with dry roads and temps in the 60's computed to 52.5 mpg on gas and nearly 70 miles on electric for nearly a 140 mile round trip.