TOLEDO, OH – General Motors Chairman and CEO Dan Akerson says the auto maker’s new 8-speed transmission starting production later this year will not supplant installations of its 6-speed units.

“The 8-speed will not completely replace the 6-speed,” Akerson tells Ward’s after announcing a $204 million investment here to support production of the new gearbox.

Akerson declines to identify product programs the new transmission will support or whether it is compatible with rear-wheel-drive or front-wheel-drive powertrains.

A 2011 production launch would make GM the first domestic auto maker to offer an 8-speed transmission. Chrysler plans to introduce one in 2013.

Sizable volumes are expected from the GM gearbox, given the technology’s potential for delivering improved fuel economy and new stricter corporate average fuel economy targets due in 2016.

In Toledo, which receives a $204-million chunk of some $2 billion in manufacturing investment, plans are to produce 6-speed units alongside the 8-speed for the foreseeable future, GM tells Ward’s.

Last year, in a depressed market, Toledo built more than 637,000 FWD and RWD automatic transmissions. A key customer for Toledo is the Chevrolet Cruze, a prime arrow in GM’s quiver as it seeks to hit the 35.5 mpg (6.6 L/100 km) CAFE target.

Akerson also updates production of the Chevy Volt extended-range electric vehicle. Its Detroit-Hamtramck assembly plant went down recently for the model-year changeover, and when it comes back up Akerson thinks there’s a good chance GM will hit its target of building 25,000 Volts this year.

“That’s contingent on battery production,” he notes, saying supplier LG Chem would need to get its new battery plant in Holland, MI, fully up and running.

So far, Volt sales have been off that pace, accounting for 1,703 deliveries in the year’s first four months, according to Ward’s data. GM has said a number of units have been going to dealers as demonstration models.

United Auto Workers union Vice President Joe Ashton joins Akerson for the Toledo announcement and says GM will begin hiring new workers soon. Just 1,300 UAW members remain in a pool of laid-off employees, and GM’s big investment this year calls for creating or retaining some 4,000 jobs.

Despite the massive investment plan – GM says it will announce more sites to receive money in the coming months – it remains unclear if the auto maker will restart idled assembly plants in Spring Hill, TN, or Janesville, WI.

Ashton says those sites will be a topic of this year’s contract negotiations. The UAW’s deal with GM expires in the fall.

GM’s Shreveport, LA, plant also will be on the agenda, Ashton says. Unlike Spring Hill and Janesville, it was dumped into a group of assets slated for liquidation.

The plant has no new product scheduled after it stops building current-generation small pickups next year.

“No doubt (Shreveport) is in a different situation,” Ashton tells Ward’s. “But I’m sure GM could get it back for a dollar if they wanted.”

Ashton also reiterates this year’s negotiations will be more about saving jobs than trying to jettison the controversial 2-tier wage agreement GM won for select sites.