We all know that the 2014 Ford Mustang will bring about the end of the reign of the S197 platform. Introduced in 2004 for the 2005 model year, the S197 platform has now undergone two major redesigns since its debut, as well as the inclusion of a new line of engines that saw the return of the familiar 5.0 moniker. An inside source has let it slip that the next Mustang platform will be called the S550.

Mustangs Daily has learned through an anonymous source that this new moniker will grace the 2015 Mustang, which celebrates 50 years as America’s favorite muscle car.

The S-designation began in 1993 with the introduction of the 1994 Mustang, based on the then-new SN95 platform. Ford has never really explained where these designations come from, but Ford fans have grown to know and love them. We’re sure whatever Ford has planned for the 2015 Mustang, the S550 platform will soon find plenty of fans of its own.

While nothing has been confirmed yet, rumor has it that the 2015 Mustang S550 will be smaller, lighter, and will probably pack an EcoBoost four-cylinder engine. The 5.0 will still be an option as well, and styling will likely follow the design architecture revealed with the Ford Evos concept (pictured above). The 2015 Mustang will also finally get an independent rear suspension standard, something Mustang fans have been asking for for a long time now.

With just over a year until S550 Mustang sales begin, we’re in the final stretch of waiting. 2014 can’t come soon enough.