General Motors announced Thursday that it has broken ground on an expansion of its engine plant in Spring Hill as a part of a $788 million investment the company announced earlier this year in April.

Following the announcement of the investment in April, GM officials said the vast majority of the $788 million would go toward engine production in Spring Hill’s powertrain facilities. One of the focal points of the investment is new high-efficiency engine production.

The focus on higher efficiency engines at GM comes in response to federal government standards for auto manufacturers to have an average fuel economy of 54.5 miles per gallon on a fleet basis for the 2025 model year.

GM broke ground on the expansion of its engine plant on Wednesday, Oct. 5.

“The fact that we are not just adding a building,” said Tom Engle, plant launch operations manager, “but actually blasting into the rock formation one more time, is an absolute testament to this site and this workforce’s commitment to make the world’s best propulsion systems.”

Since 2010, GM has invested more than $2 billion in Spring Hill to add new vehicle and engine lines to the plant’s powertrain and assembly facilities. Almost half of that has been invested in Spring Hill in just the past year.

In addition to the $788 million announced in April, GM announced a $148-million investment in February to repurpose flexible machining and assembly equipment to build the Small Block 6.2L V8 engines for GM’s trucks.

Company officials said in April that the latest $788 million investment would mean the addition of nearly 800 new jobs.

“The ground breaking for the Spring Hill Manufacturing plant expansion, for a new engine program, strengthens the job security for all of our Tennessee team members,” said UAW Local 1853 Chairman Mike Herron.

Workers at the Spring Hill plant have produced more than 5 million Ecotec 4-cylinder engines at benchmark quality and efficiency. Since then, the site has successfully launched three other engine lines, including a V8 engine that was launched in record time, according to a news release.

“General Motors knows they can count on the Spring Hill team to launch and build the next generation engines that will power GM products in the future,” Herron said, “at the highest quality levels and at a very cost-competitive rate. These are two very important factors in awarding new work to any GM facility. We are very proud of our UAW workforce in Spring Hill. They continue to build the best engines in the world, powering GM’s products of the future.”

During a shutdown of the vehicle assembly plant at Spring Hill from 2009 to 2011, the engine plant continued in operation.

Now GM Spring Hill Manufacturing’s engine plant helps supply various GM assembly plants around the globe. The site’s current operations also include assembly of the Cadillac XT5 and GMC Acadia, a stamping plant, a body shop, a paint shop and two polymer injection molding operations.