Once considered the future of the U.S. auto industry, the former Saturn plant in Spring Hill, Tennessee, is getting a $233 million makeover to build the Cadillac SRX and possibly other vehicles.

It was originally hailed as the future of the U.S. auto industry, only to be mothballed in the wake of General Motors’ bankruptcy and the abandonment of the maker’s failed Saturn brand. But GM is about to make a major investment in its Spring Hill, Tennessee assembly plant that will turn the sprawling complex into one of its most flexible and promising factories.

The announced of a $233 million investment comes a quarter century after the Spring Hill plant first opened as the home of the once-promising Saturn brand. While Saturn was one of four brands abandoned as GM emerged from its 2009 bankruptcy, the powertrain portion of the Tennessee complex will produce a critical new line of small gasoline engines, while the adjacent assembly line will be re-tooled to handle upcoming midsize models.

While GM isn’t ready to tip its hand on all its plans, it did confirm that Spring Hill will assemble the next-generation version of Cadillac’s popular SRX crossover-utility vehicle. At least one other midsize model is expected to go into the factory which will be flexible enough to handle a wide range of products in the future.

“This is an all-around good news story for our members in Spring Hill and Bedford,” said United Auto Workers Union Vice President Cindy Estrada, head of the union’s GM Department. “We worked with GM to create this success story through the collective bargaining process.”

GM and the UAW have long had an unusual relationship in Spring Hill. When then-GM Chairman Roger Smith first announced the Saturn program, he said the plan would require the union to agree to significant changes in traditional contract language. The UAW ultimately agreed to a separate agreement that allowed far more flexibility than in a typical GM plant, making it possible to profitably produce a small car in the U.S. when GM was losing money on larger, higher-priced models.

GM's taking the wraps off its former Saturn plant in Spring Hill, Tennessee, to produce the Cadillac SRX crossover and potentially other vehicles too.

Despite that, Saturn never quite lived up to its initially high expectations, largely because GM never invested in the broad range of products analysts said the brand needed. And so, when the maker went broke in 2009, Saturn was tossed on the rust heap, Spring Hill was mothballed and seemed likely to be closed permanently, like a number of other GM plants.

But as the maker started to rebound, company officials hinted that the factory might be ripe for rebirth, the maker recently announcing it would invest $350 million for two midsize models that would go into Spring Hill, helping create or retain 1,800 jobs. The latest $233 million investment comes on top of that, and is expected to translates into 100s of additional jobs.

As significant as the Cadillac SRX news might be, the decision to build the new Ecotec engine family in Tennessee could be even more far-reaching. The portfolio will include 11 different 3- and 4-cylinder powertrains, ranging from 1.0 to 1.5-liters, and developing from 75 to 165 horsepower. They will be used by five different GM brands here and abroad, powering a planned 27 different models by the 2017 model-year, including some of GM’s highest-volume global product lines.

“The new Ecotec engine family represents the most advanced and efficient small displacement gasoline engines in GM’s history,” said Arvin Jones, GM North America manufacturing manager.

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The new engine line-up will be produced alongside GM’s existing 4-cylinder Ecotec engines used in such vehicles as the Chevrolet Malibu and Chevy Impala.

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Today’s announcement is the latest in a string of good news for the State of Tennessee. Earlier this summer, Volkswagen AG announced it will roughly double the size of its assembly plant in Chattanooga to build a new midsize SUV based on its CrossBlue concept.

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Meanwhile, GM’s plans for Spring Hill will have a ripple effect. As many as 500 new jobs will be created at a nearby supplier park servicing the plant, while another 230 jobs – and $25.5 million in investment money – will land in Gallatin, an hour away.

The Saturn complex, built on an old farm, brought about 7,000 jobs to Spring Hill at its peak. By the time the factory was idled it looked as if the era of high-paying manufacturing jobs would be short-lived. The new plans for Spring Hill aren’t likely to see employment reach anywhere near that old peak, but GM’s investment suggests the community won’t have to worry about a return to farming anytime soon.