Why Do PHEVs Get Two MPG Ratings & What Do They Mean?

As the major players in the automotive arena continue to pivot away from the use of fossil fuels to power their vehicles, new technologies are making it easy for consumers to go green whenever they get behind the wheel. But once you get past which make, model, and brand of vehicle you want to go green with, there's still an option or two to consider, primarily if you want to purchase an Electric Vehicle or a Plug-In Hybrid Electric Vehicle.

Those names are, of course, often shortened to EVs or PHEVs, and designate the engine setup of each vehicle. In the case of the former, rechargeable batteries are used to power the vehicles in lieu of gasoline. Given that fact, it'll come as little surprise that their fuel economy is not subject to the traditional rating that is applied to cars, trucks, and SUVs powered by gasoline. Rather, their fuel economy is rated by the distance they're able to travel before the battery needs to be charged.

In the case of PHEVs, as the "H" stands for hybrid, you'd be correct in thinking that the name is indicative of an engine that utilizes both gasoline and rechargeable batteries to function, though, unlike standard hybrids, they tend to rely more on the latter for day-to-day driving. As such, PHEVs are subject to the fuel economy ratings for both gas powered vehicles and electric vehicles. Those ratings are typically dubbed MPG, and MPGe by automakers. Here's what those designations mean. 

With gas prices continuing to err on the higher side, new car buyers tend to put extra emphasis on a vehicle's MPG rating. However, you might be wise not to put too much emphasis on MPG, as it can vary dramatically based on driving habits. Of course, apart from embracing an eco-friendly vehicular edge, the possibility of saving a few bucks at the fuel pump has been a motivating factor for many to embrace the EV and PHEV movement.

If you're eyeing a vehicle in the second category, you've no doubt spent considerable time examining both its MPG and MPGe ratings, with the latter acronym standing in for Miles Per Gallon Equivalent. The word "equivalent" is important there, as the rating is, essentially, intended to convert how much power a battery uses to travel a single mile into the equivalent of the same number for gasoline. As with MPG, several factors can contribute to variations in a vehicle's MPGe rating, so it's best to do your research on any vehicle you're considering.