General Motors will invest $275 million into its Spring Hill, Tennessee, facility.

$150 million will go ‘to support a future Cadillac internal-combustion product.’

The facility currently builds four models, and this future Cadillac will be its fifth.

General Motors recently announced that the company is investing $275 million into its Spring Hill, Tennessee, facility. Part of that investment—$125 million—will go to support the continued production of the automaker’s 2.7-liter engine. GM has earmarked the rest for a future combustion-powered Cadillac.

In the press release, the Detroit automaker said it would spend $150 million at the plant "to support a future Cadillac internal-combustion product." What product the factory will build is a mystery, but it’s likely something new.