Augment a typical gasoline engine with a fully electric motor, tether it to a battery pack and voila, you’ve got yourself a super fuel-efficient cruiser. When it comes to exceptional fuel-economy, it doesn’t get much better than what a hybrid car can deliver. While the initial cost of such a vehicle may be a significant amount more than a gasoline-only-powered counterpart, the savings come in the form of reduced fuel expenses over time. Over the last decade HEVs and PHEVs alike have been increasing in popularity in the USA for more than just their great fuel economy, but for their eco-friendly traits too. Here are the most fuel-efficient HEVs and PHEVs in the USA today:

Hyundai Ioniq Blue - As the base model of the Ioniq lineup, the Blue is kept relatively rudimentary in its equipment and bare of features in comparison with the higher-tier models. It’s because of this, however, that it’s the most fuel-efficient trim from the lineup and the best hybrid in the USA in terms of miles per gallon performance. With its 1.6-liter four-cylinder hybridized engine and six-speed automatic gearbox, the Blue returns EPA estimated gas mileage figures of 57/59/58 mpg city/highway/combined.

Toyota Prius Eco - The Toyota Prius Eco is equipped with a hybridized 1.8-liter four-pot mill that’s coupled with a CVT automatic, combined outputs are rated at 121 hp. With this powertrain, the well-known Prius Eco delivers fuel consumption rates of 58/53/56 mpg on the EPA drive cycles. Because of its liftback or coupe-like body configuration, the Prius Eco is afforded plenty of cargo room, boasting an expansive 27.4 cubic-feet behind the back seats.

Honda Insight - At an MSRP of only $22,930, the Honda Insight arguably has one of the more attractive affordable fun-to-drive factors as a hybridized vehicle. Under its hood is a 151 horsepower 1.5-liter four-cylinder electrified mill mated to a CVT automatic. Driven cautiously, this enjoyable eco-friendly sedan will give drivers gas mileage figures of 55/49/52 mpg. Unfortunately, the insight isn’t as practical as most of the competition, offering up only 15.1 cubes of cargo room in its trunk. 

BMW i3 - Technically, the standard i3 is a fully electric vehicle, only with the optional range extender does it essentially become a plug-in hybrid. While a single AC electric motor and 42 kWh battery pack are the primary sources of power, a 0.6-liter two-cylinder gasoline engine acts as the range extender add-on. With this setup, the i3 is capable of returning 124/102/113 MPGe city/highway/combined and is estimated to deliver 200 mi on a full tank of gas and fully charged battery.

Chevrolet Volt - A gasoline-powered 1.5-liter four-cylinder engine, dual electric motors, and an 18.4 kWh lithium-ion battery pack cede power to the front wheels of the Chevy Volt. In hybrid mode, the compact hatch will give drivers 42 mpg, on electricity alone that figure increases to 106 MPGe. As a true hybrid vehicle, the Volt’s 53-mile all-electric range is class-leading, despite the i3’s vastly superior figure.

Toyota Prius Prime - The car that paved the way forward for all plug-in hybrid’s that exist today, the venerated Toyota Prius Prime may not be the best performing vehicle in its class, but a top contender nonetheless. Powered by a 1.8-liter inline-four combustion engine and a couple of electric motors, this midsize sedan earns 55/53/54 mpg on the EPA drive cycles or 133 MPGe combined. On electrons alone, it should reach a range of around 25 miles before requiring a recharge.