DETROIT – The 2013 Chevrolet Malibu Eco with eAssist technology is the most fuel-efficient Malibu ever – delivering a GM-estimated 37 mpg on the highway, thanks to smart electric technology that doesn’t affect ride or performance.
The 2013 Malibu Eco is the first Chevrolet vehicle to feature eAssist. Along with specific aerodynamic enhancements, it achieves 12-percent greater highway fuel economy than current models equipped with the 2.4L engine.
“Malibu Eco’s eAssist system integrates regenerative braking with the latest lithium-ion battery technology, to give our customers significant fuel-efficiency gains,” said Steve Poulos, global chief engineer of eAssist. “Providing electric boost to the powertrain system during heavy acceleration and grade driving helps the transmission operate more efficiently. The engine’s start-stop and fuel shut-off during deceleration features add to the fuel savings.”
The eAssist system is made up of a 32-cell, 0.5-kW lithium-ion battery, an electric motor-generator and next-generation six-speed transmission. The system’s electric motor-generator is mounted to an Ecotec 2.4L four-cylinder engine, in place of the alternator, to provide both motor assist and electric-generating functions through a revised engine belt-drive system. The motor-generator is a high-performance, compact induction motor that is liquid-cooled for increased performance and efficiency.
The air-cooled 115V lithium-ion battery is integrated into a power pack located in a compartment between the rear seat and trunk. The power pack is surprisingly compact and lightweight, weighing only about 65 pounds (29 kg). It allows rear access to the trunk via the split-folding rear seat, unlike other hybrid competitors. Trunk space is slightly reduced from 2011 models, but still offers 14.3 cubic feet (405 liters) of storage for luggage, golf clubs and other large items. An electric fan cools the power pack, drawing air from a vent located in the package tray, behind the rear seat.
The induction motor-generator bolsters the engine with approximately 11 kW (15 horsepower) of electric power assist during heavy acceleration and 15 kW of regenerative braking power. This power capability enables the battery to capture energy during regenerative braking for improved fuel economy.
e Assist technology also allows for a numerically lower 2.64 final drive ratio. As a result, the Malibu Eco can travel 580 highway miles (965 km) between fill-ups, despite having a smaller (15.8-gallon / 59.9 L) fuel tank than other 2013 Malibu models (18.6-gallon / 70.4 L).
The system also enables the Ecotec engine to shut down fuel delivery in certain deceleration conditions, which saves fuel. While in fuel shut-off mode, the motor-generator unit continues spinning along with the engine to capture regenerative braking power and provide immediate and smooth take-off power when the driver presses on the accelerator. Then, as the vehicle comes to a stop, the motor-generator unit spins the engine, bringing it to a smooth stop – and properly positions it for a smooth and seamless restart.
“The battery system is designed to provide power assistance to the internal combustion engine, rather than storing energy for all-electric propulsion,” said Poulos. “It’s really an extension of the conventional internal combustion engine, not a replacement for it.”
Additional fuel-saving features include:
A power flow display in the driver information center – or the center console screen when equipped with the navigation system – indicates which of the following modes the Malibu Eco is operating in:
Driver-selectable modes are offered to enable maximum comfort or efficiency of the air conditioning system and include:
2.4L Ecotec engine and next-generation six-speed
The eAssist system works with Malibu’s 2.4L Ecotec four-cylinder engine, which features fuel-saving variable valve timing and direct injection technology. It is rated at 182 horsepower (136 kW) and 170 lb.-ft or torque. That’s 13 more horsepower and 12 more lb.-ft of torque than the previous Malibu. – and it’s more power and torque than the 2012 Toyota Camry Hybrid, 2012 Hyundai Sonata Hybrid, and 2012 Ford Fusion Hybrid.
The next-generation Hydra-Matic 6T40 six-speed transmission is designed to enhance powertrain efficiency.
Significant internal transmission changes to clutch controls and hardware provide reduced spin losses while improving shift response and time. The added electric power provided by the eAssist system allows for higher gearing to improve steady state efficiency without impacting acceleration performance or driveability. The system’s ability to provide some electric assistance at cruising speeds allows the driver to accelerate lightly or ascend mild grades without the transmission downshifting. Automatic Grade Braking keeps the transmission in a lower gear when decelerating or coasting on a downgrade, helping to improve brake wear performance.
An auxiliary, electric-driven transmission oil pump is added to the 6T40, which keeps the transmission primed and the fluid flowing when the engine shuts down at a stop. That keeps the transmission ready to perform when the driver accelerates, for a seamless, uncompromised driving experience.
“It’s a very integrated powertrain system, with no compromises in driving performance, shift quality or ride and handling,” said Todd Stone, Malibu lead development engineer. “We believe this combination points to the future of vehicles powered primarily by an internal combustion engine.”
Founded in Detroit in 1911, Chevrolet celebrates its centennial as a global automotive brand with annual sales of about 4.25 million vehicles in more than 120 countries. Chevrolet provides consumers with fuel-efficient, safe and reliable vehicles that deliver high quality, expressive design, spirited performance and value. The Chevrolet portfolio includes iconic performance cars such as Corvette and Camaro; dependable, long-lasting pickups and SUVs such as Silverado and Suburban; and award-winning passenger cars and crossovers such as Sonic, Cruze, Malibu, Equinox and Traverse. Chevrolet also offers "gas-friendly solutions including Cruze Eco and Volt. Cruze Eco offers 42 mpg highway while Volt offers 35 miles of electric, gasoline-free driving and an additional 344 miles of extended gasoline range, according to EPA estimates. Most new Chevrolet models offer OnStar safety, security and convenience technologies including OnStar Hands-Free Calling, Automatic Crash Response and Stolen Vehicle Slowdown. More information regarding Chevrolet models, fuel solutions, and OnStar availability can be found at www.chevrolet.com.
Malibu Eco Story