General Motors says its 2014 Chevrolet Malibu midsize sedan is the first in the category in the United States to be offered with standard stop-start engine technology designed to save fuel and lower emissions.
The technology has been finding increasing favor in other industrialized markets, namely those in Europe, where pollution legislation is tighter and fuel prices are higher than those we experience here. The GM press release said the technology will help the 2014 Chevrolet Malibu improve its city fuel economy by 14% over the outgoing Malibu to 25 MPG. The technology automatically shuts down the engine when the car comes to a complete stop — for example, at a stoplight — then automatically restarts the engine when the driver’s foot is removed from the brake. A 12-volt auxiliary battery powers accessories such as radio, HVAC, and power windows while the engine is stopped in those situations, GM said.
Malibu Chief Engineer Todd Pawlik said, “The key was to apply the knowledge we gained from our eAssist technology. By leveraging knowledge from the stop/start system we use on eAssist, we were able to significantly improve city fuel ratings by 3 mpg, or 14 percent on Malibu’s entry-level 2.5L model, compared to the 2013 model.”
The release said the 2014 Chevrolet Malibu’s stop-start system monitors a number of factors to determine whether to shut down the engine, including braking force, HVAC system load, and vehicle speed to determine whether shutting down the engine would be more efficient than allowing it to run as normal.
The 2.5-liter four-cylinder base engine in the 2014 Chevrolet Malibu is rated at 36 MPG highway by the EPA, bringing its combined fuel economy rating to 29 MPG, besting most of its competitors in the segment, if only just. Those competitors include the 2014 Toyota Camry with its standard 2.5-liter four-cylinder, which is rated at 25 MPG city, 35 MPG highway, and in our experience pulled down just shy of 29 MPG combined. Other fuel saving technologies Chevrolet used to boost the Malibu’s fuel economy:
- Intake Valve Lift Control, a system that allows the engine to pump in only the air that it needs to meet the driver’s demands for power. Think of it as a way to make sure the engine is as lean-burning as possible while light throttle pressure is used during cruising, but also a way to allow the engine to make ample power when called upon. GM says the system boots low-RPM torque for a greater sensation of power at lower engine speeds, which in theory should help drivers keep their foot out of the deeper regions of throttle travel during day-to-day traffic and yield better fuel economy.
- A new six-speed transmission, dubbed the 6T45, makes its debut in the 2014 Chevrolet Malibu. It has been tweaked to reduce the energy needed to pump transmission fluid, further enhancing fuel efficiency.
Why all this work on the 2014 Malibu? Because not making incremental improvement in the hotly contested midsize sedan segment would be a surefire way to let GM’s competitors get the edge, reckons Chevrolet Marketing Vice President Chris Perry.
“In this competitive midsize segment, there is no standing still,” Perry said.