Sometimes, two really is better than one.
Many new cars feature engine start-stop systems, but few have a special feature found on the one used for the 2014 Chevrolet Malibu.
That's because the Malibu's system uses two batteries. Like most gasoline cars, it has a 12-volt battery under the hood, but models equipped with the start-stop system have a second 12-volt battery mounted in the rear.
Here's how it works.
The 2014 Malibu will shut off its engine when the car is stationary under certain traffic conditions, such as stoplights. Nothing out of the ordinary there for any hybrid driver.
When the engine turns off, the second battery kicks in to provide power to electrical accessories, including lights, audio, climate control, and powered items like windows and door locks.
Note that while the climate control stays on, it operates at reduced power with the engine off.
Drivers can select either maximum air-conditioning power or maximum efficiency. If priority is given to the air conditioning, the engine shuts off less frequently--or not at all--while the cool air is blowing.
An auxiliary electric hydraulic transmission pump also keeps the gearbox primed with fluid while the engine is shut off.
This takes some of the load off the first battery, which Chevy says provides quicker restart times. The start-stop system also comes with a tandem-solenoid starter to help wake the engine up faster.
Start-stop comes standard on 2014 Malibus equipped with the base 2.5-liter four-cylinder gasoline engine. Heavily updated after just a single year in production, its output is 196 horsepower and 186 pound-feet of torque.
So equipped, the 2014 Chevy Malibu is rated at 29 mpg combined (25 mpg city, 36 mpg highway) by the EPA.
That means the base Malibu now equals the pricier Malibu Eco mild hybrid in all three test cycles. The base Malibu starts at $22,965 including destination; the Eco starts at $26,670.
The Malibu Eco uses an older 2.4-liter four-cylinder engine, a belt-driven starter-alternator unit, and a small lithium-ion battery pack. Branded eAssist, GM also offers that system in the Buick Regal and Buick Lacrosse.
With the same gas mileage--and no large battery pack taking up trunk space--the 2.5-liter 2014 Malibu may have made the Eco obsolete. At least for this year.