Fuel economy requirements are about to increase and carmakers are going to be scrambling to find ways to squeeze more miles out of a gallon of gas. And to do it, automakers are going to count on the electric motor and battery to help.
General Motors is reintroducing its “mild hybrid” system as eAssist on some Buick models and this Chevrolet Malibu, dubbed Eco. A similar system was available briefly as GM’s first hybrid system on the Saturn Vue.
While most “full hybrids” have an electric motor sandwiched in between the gas engine and transmission, eAssist replaces a typical car’s alternator with a larger generator that is rated at 15 kW and provides up to 15 extra horsepower. The motor turns the engine crank by a thick belt. The system is can briefly – very briefly – propel the car until the gas engine restarts when the car is stopped. It can also give the engine a little extra oomph for the drivetrain while cruising or for passing slower traffic.
The result? Fuel mileage increases from 22 mpg city and 33 highway to 25/37, neatly bridging the gap between regular gas-only mid-sizers and full hybrids such as the Kia Optima. We saw 29 mpg in a mix of freeways and rural two-lanes. Contrast that with mileage of a Buick Verano, tested the week before. With the same 2.4-liter four cylinder engine, but no eAssist, the smaller Verano averaged 26 mpg.