AUSTIN, TX – Expect eAssist, the newly launched advanced stop/start system from General Motors, ultimately to command a modest share of the mix on the redesigned-for-’13 Chevrolet Malibu, WardsAuto learns.

The system will be available on the Malibu Eco in the first quarter of 2012. Mated to a 6-speed automatic transmission, eAssist will be the only powertrain available for the nameplate until a pair of new 4-cyl. engines arrive in the second half of the year.

After the redesigned Malibu lineup has its full complement of powertrain choices, expect its mix to settle between 10% and 15% of units sold, says Russ Clark, director of marketing for midsize and performance cars and small cross/utility vehicle at Chevrolet.

The eAssist system combines a 2.4L 4-cyl. engine with a 115V lithium-ion battery pack and 15-kW (20-hp) electric motor-generator to save fuel. The engine shuts off at stops and restarts after the driver releases the brake. It also provides mild assist when climbing grades or accelerating heavily.

Clark says eAssist’s chunk of Malibu sales will not be limited by manufacturing capacity or the availability of Li-ion batteries and electric motors. GM will continue to build the redesigned Malibu at its Fairfax, KS, assembly plant, and also will produce units as demand warrants at the auto maker’s Detroit-Hamtramck, MI, facility.

Battery availability has contributed to a slow production start for the Chevy Volt extended-range electric vehicle.

“We’ll do as many as the market wants,” Clark tells WardsAuto at a media event here for Malibu Eco. “We won’t have a problem.”

Through November, the Malibu was on track to sell some 202,000 units this calendar year, according to WardsAuto data, making it likely the Malibu with eAssist would account for between 20,000 and 30,000 units.

GM debuted eAssist earlier this year on the ’12 LaCrosse. The auto maker says the LaCrosse eAssist has been popular, staying on dealers lots fewer than 15 days.

The dealer order mix for the eAssist-equipped Buick LaCrosse fullsize sedan was 30% in October and November.

But unlike the LaCrosse, which features eAssist as the base powertrain, GM will ask a $2,600 premium for a Malibu Eco, compared with a similarly equipped ’12 Malibu.

Clark does not see the Chevy Volt’s battery controversy influencing Malibu Eco purchase decisions.

The National Highway Traffic Safety Admin. opened a formal investigation into the Volt’s battery pack after units severely crashed during safety tests caused two fires days later. A fix is not expected soon for the Volt battery pack, which is vastly larger than that in the eAssist system.

“Part of advancing technology forward is learning how to manage and cope with it,” Clark says.

As such, dealer training and advertising will focus entirely on the fuel-savings benefits of buying a Malibu Eco. The car promises a 12% improvement in fuel economy, compared with its predecessor, while its electric motor-generator adds 15 hp, boosting performance.

“The best thing is for customers to take it for a test drive,” Clark says, discounting any potential reluctance U.S. buyers might have to start/stop technology, which has been saving fuel for consumers in other global markets for a number of years.

“Consumers are adaptable. I keep looking at this,” he says, pointing to his smart phone. “You’d have never imagined something like this five years ago. Now, how could you live without one?”

Proliferation of eAssist through the Chevy portfolio will be a model-by-model decision, Clarks says, because the benefits of the technology are proportional to vehicle size.

“You’ll see it grow in passenger cars, for sure,” he says. “It will be a portion of car lines.”

The eAssist system represents a key play for GM to meet stiffening corporate average fuel economy standards, which start with the ’12 model year and peak at 35.5 mpg (6.6 L/100 km) for U.S. auto maker fleets in 2017.

The next-generation Malibu will not offer a V-6 engine, which has a take rate of less than 10% on current models. In addition to eAssist, the ’13 Malibu also will offer an all-new 2.5L 4 cyl. engine with direct injection, a next-generation application of the current 2.4L DI engine, a Ward’s 10 Best Engines winner.

The Malibu also will receive a turbocharged 2.0L 4-cyl. engine, likely with DI technology. GM’s current-generation turbo 2.0L Di 4-cyl. also is a 2012 Ward’s 10 Best Engines winner.