GM Shaves 1 MPG Off Chevy Malibu Eco Fuel-Economy Estimates

General Motors dials back fuel-economy estimates on the Chevrolet Malibu Eco, a redesigned-for-’13 model with mild-hybrid technology arriving in the coming weeks, citing a better balance between performance and efficiency.

The Malibu Eco will achieve an estimated 25-37 mpg (9.4-6.4 L/100 km) city/highway, down from the 26-38 mpg (9.0-6.2 L/100 km) GM predicted at the car’s reveal in April and during pre-production drives of the car in September.

During testing of production models last month, WardsAuto achieved an average of 26.6 mpg (8.8 L/100 km) in mostly city driving.

GM blames the 1-mpg difference on refinements through the development process, noting “fuel economy has many interactions with vehicle attributes such as drive and shift quality, vehicle dynamics and stopping distance, among many other factors.

“We balanced the vehicle to deliver the best overall performance,” the auto maker says in a statement.

The Malibu Eco’s updated fuel-economy numbers mark a 12% improvement over ’12 model-year units with a 2.4L 4-cyl. engine.

The Malibu Eco uses eAssist, which combines old-fashioned internal-combustion technology with an advanced 115V lithium-ion battery pack and 15kW (20-hp) electric motor-generator for V-6 power in a smaller, more-efficient package.

With eAssist, the Malibu Eco’s 2.4L 4-cyl. engine shuts off at idle and restarts after releasing the brake pedal. The transition occurs in a split second. The electric motor-generator also provides some boost during heavy acceleration, such as a passing maneuver or climbing a grade.

GM pulled ahead production of the Malibu Eco by about six months to beat rivals to market with a fresh entry in the competitive midsize passenger-car segment. Redesigns of the Honda Accord, Nissan Altima and Ford Fusion are expected to arrive this fall.

The Malibu Eco will be the only model available for the first six months before a base-level variant of the eight-generation car with an all-new 2.5L 4-cyl. engine arrives.

That engine portends a 12% boost in horsepower and a 16% gain in torque over the current 2.4L 4-cyl., a Wards 10 Best Engines winner two years ago, without sacrificing fuel economy.

GM also plans to outfit the redesigned Malibu with a 2.0L turbocharged 4-cyl. engine, although few details of that powerplant have been made public.

The Malibu Eco represents GM’s second bid at applying mild-hybrid technology to the nameplate.

A Malibu Hybrid bowed in 2008 with the car line’s seventh-generation redesign, but it floundered in the market because its fuel economy trailed models with a traditional 4-cyl. engine and the technology came at a premium. That hybrid variant was discontinued after two model years.

GM launched eAssist on the ’12 Buick LaCrosse late last year and it also will appear in the Buick Regal. The technology serves as the base powertrain for the LaCrosse. GM will charge extra for it on the Malibu and Regal.

eAssist is expected to roll into other GM cars in the future, as the auto maker works to meet new federal fuel-economy standards peaking at 35.5 mpg (6.6 L/100 km) in 2016 and consumers look to tighten their spending at the pump.

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