With the debut of its 2013 Chevrolet Malibu, General Motors continues to leverage its Global Epsilon D-segment architecture. Introduced simultaneously at the Shanghai and New York auto shows in April, the all-new Malibu (GMX351) is based on the short-wheelbase version of Global Epsilon, which currently underpins the Buick Regal and Opel/Vauxhall Insignia.
Slated to enter production at the Hamtramck, MI, plant in May, the new Malibu will be the first midsized Chevrolet ever to be sold globally. The retail plan includes sales in more than 100 countries. The incumbent model was introduced in 2004 and is GM’s biggest-selling passenger car. “We have high expectations for global sales of the new Malibu, as the D-segment is the highest volume vehicle segment worldwide,” Jim Dolot, Malibu’s Vehicle Line Executive, told AEI.
Malibu launches in two models. Coming first in late spring is the ECO version that employs GM’s new eAssist mild-hybrid system introduced on the 2012 Buick LaCrosse and Regal. The system, combined with a comprehensive aerodynamic package (0.29 Cd) and reduced rolling resistance, will provide 26 mpg city/38 mpg highway estimated fuel efficiency, according to Chief Engineer Mark Moussa. Non-hybrid versions of the car, in LS, LT, and LTZ trim levels, enter production in summer 2012.
The new Malibu rides on a 107.8-in (2738-mm) wheelbase, 4.5 in (114 mm) shorter than the outgoing 2011 model, that is not shared with the other Global Epsilon models, said Moussa. The 62-in (1574-mm) front and rear tracks are more than 2 in (51 mm) wider than the incumbent model. The 191.3-in (4859-mm) overall length is 0.5 in (12.7 mm) shorter.
GM claims the car’s interior has nearly four cubic feet (113 L) of additional volume compared with the 2011 model. Front shoulder and hip room are increased 1.5 in and 2.7 in (38 mm and 69 mm), respectively. Rear shoulder room, at 57.1 in (1450 mm), is 3.2 in (81.3 mm) more accommodating, but overall the rear passenger space feels tighter than that of the outgoing Malibu. (Full disclosure: the writer is 6 ft 3 in or 1.9 m tall.) GM claims more than 1 ft³ (28 L) of additional trunk volume.
Moussa’s development team wrestled with attenuating the “mass creep” that affects most new vehicle programs due to added feature and safety content. While the base LS model drops one EPA test-weight class compared with the 2011 Malibu, average curb weight across the model range increased slightly, he said. Hyundai Sonata, Honda Accord, and Toyota Camry served as the main development benchmarks, Moussa said.
The all-steel body-in-white is comprised of 65% (by mass) high-strength and ultrahigh-strength alloys, Moussa noted. Bending and torsional rigidity are both improved significantly vs. the current Malibu, although GM engineers would not provide specific frequency data. Acoustic laminated windshield glass is new for 2013; balancing its NVH benefits with added mass “is always a trade-off,” Moussa noted. Mass-reduction countermeasures include replacement of the incumbent steel rear suspension knuckles with aluminum castings and a tire-inflator kit in lieu of a spare on the base model.
The 2013 model retains the basic suspension design (front McPherson struts, four-link rear) and adds ventilated rear brake rotors, an electric parking brake, and enhanced Stabilitrak system. Active crash mitigation technology includes a front-camera-based lane-departure warning system, radar-based forward collision avoidance, and a rear-view backup camera.
60-count aero reduction
Styling Director Bryan Nesbitt’s team incorporated cues from the Camaro into Malibu’s body surfacing and interior elements. Most notable are the quad taillamps and instrument cluster. Function also follows the evolutionary form; the GMX351’s body engineers worked with the company’s aerodynamics experts to remove approximately 60 counts of wind drag from the new Malibu, compared to its predecessor.
According to Nesbitt, the hundreds of hours spent fine-tuning the body in GM’s wind tunnel included, for example, shaping the car’s front corners to provide laminar airflow along the body sides to the rear of the vehicle.
Both Malibu and ECO feature active grille shutters. Similar to the system used on the Chevy Cruze and Buick LaCrosse, it automatically closes airflow through the lower front intake opening according to engine cooling demand. The electromechanical shutter is opened or closed based on engine coolant temperature and vehicle road speed. For example, the shutters open when the car is traveling up a hill, pulling a trailer, or in hot city driving; they close at highway speeds when engine cooling is required less. When closed, the shutter system enhances aero performance by redirecting airflow around the front of the vehicle and down the sides, rather than through it.
Four underbody panels cover approximately 50% of the vehicle underside, providing a clean flow path under the vehicle. The standard tires are engineered for low rolling resistance.
eAssist enables 550-mi range
The Malibu ECO’s eAssist stop-start system combines a 180-hp (134-kW) direct-injected 2.4-L Ecotec four, 6T40 6-speed automatic transaxle, Hitachi-supplied 115-V air-cooled lithium-ion battery pack, and belt-driven motor/generator supplied by Continental. The system is capable of producing approximately 11 kW (15 hp) of electric power assist during hard acceleration and 15 kW (20 hp) of regenerative braking power.
The liquid-cooled, induction-type motor/generator unit delivers 79 lb·ft (107 N·m) and provides electric-only operation at very low speeds.
The pack, which is located in the trunk behind the rear seat, includes an integrated power inverter and 12-V power supply. It has a working state-of-charge window of about 20% and is cooled by a small electric fan that draws air from the cabin, according to system Chief Engineer Steve Poulos. The electrified power system enables the internal-combustion engine to shut down fuel delivery in certain deceleration conditions. Total pack mass is 65 lb (29 kg); the pack’s peak power density is 518 W/kg.
A hill-assist feature captures brake system pressure to help keep the car stationary when eAssist’s start-stop function is activated on a moderate or steep grade. This enables the driver to accelerate more smoothly from a stop.
As it does in the LaCrosse, the eAssist enables a numerically lower final drive ratio. GM engineers claim it gives the Malibu ECO up to 550 mi (885 km) in range with the 15.8-gal (60-L) fuel tank.
The 2013 Malibu will feature Chevrolet’s new MyLink infotainment package at the start of production. MyLink integrates wireless connectivity through Bluetooth to enable hands-free use of selected smart phone apps while the device remains safely stowed. It includes a high-resolution, full-color touch-screen display.