Shelby American promised a Mustang-sized announcement for December 15 a few weeks ago. That day has finally here, and it is really unique. The 2018 Mustang Shelby GT500KR brings back the King of the Road Mustang, and it's not just for show. It's also highly rare, expensive, and not confined to the 2022 model year, all of which we'll go over in more detail later.

First, let's take a look at the numbers. The supercharged 5.2-liter V8 adds a new twin-screw Whipple supercharger that displaces 3.8 liters on its own under the KR-specific carbon fiber hood. The GT500KR generates at least 900 horsepower with to improvements including a bigger throttle body, cold air intake, new intercooler, pulleys, and an enhanced exhaust system (671 kilowatts). We say at least because Shelby presently lists the power rating as 900+, so there might be a few more horsepower added before it's all said and done.

In addition to the increased horsepower, Shelby equips the GT500KR with height-adjustable front and rear springs, revised sway bars, and re-calibrated MagneRide suspension, as well as Shelby-specific 20-inch wheels. Shelby hasn't released any performance figures for the new KR, but given that a stock Shelby GT500 can run the quarter-mile in the mid-tens, the KR should be close to 9 seconds.

It should be able to handle a road course as well. Shelby also includes a carbon fiber front splitter, rear diffuser, and Gurney flaps, in addition to the aforementioned carbon fiber hood. You'll also discover accessories like billet engine caps and hood pins, and a Shelby GT500KR wouldn't be complete without lower rocker stripes. Shelby leather seats, embroidered floor mats, and unique 60th-anniversary badges honoring Shelby's inception in 1962 will be available on certain automobiles.

We use the term "select vehicles" because Shelby will not limit KR production to the 2022 model year. Only 225 will be produced in 2022, with 180 reserved for the US market and all of them being 60th Anniversary versions. Existing GT500 owners may join in the KR fun for 2020 and 2021 by submitting their cars to Shelby for a KR upfit. Those will not receive 60th Anniversary badging for obvious reasons, but they will be rarer because only 60 will be available.

Shelby quotes a price of $54,995 for the 2020-2021 upfit alone. Prices for one of the 225 KRs for 2022 begin at $127,895. That price is for an entry-level GT500; if you customize it from the factory with additional Shelby extras, the price may skyrocket. The first phase of production is set to commence in 2022.