GM Ecotec engineGeneral Motors has announced that it will invest a total of $483 million in its Spring Hill, Tennessee powertrain facility by 2012. The news comes as GM continues to move toward building more fuel-efficient engines. The automaker says that the next-generation Ecotec four-cylinder engine, complete with direct-injection, will be built in the Spring Hill plant. Those funds will also go toward bringing back a total of 483 workers that have been idle since last year.

In 2009, the company laid off 2,000 workers at the Spring Hill facility as part of its restructuring efforts, though 800 of those individuals relocated to other GM plants around the country. Even so, that didn't do much for the economy in Maury County, Tennessee. According to the Associated Press, the locality has one of the highest unemployment rates in the state – 14.5 percent in July.

Until now, the future of the Spring Hill plant had been more than a little uncertain. The facility was originally designed to produce Saturn vehicles, but was reworked to produce the Chevrolet Traverse to the tune of $600 million. GM then pulled Traverse from the plant last year.

[Sources: Associated Press via Google, General Motors]