Back in August, we reported on the fact that GM had filed to register the ZRX name. Muscle Cars and Trucks now reports that Chevrolet will be using the designation on the Silverado truck. What exactly the designation would be used for is pure speculation but given the last truck to use the ZRX designation was the sporty version of the GMC Sonoma, we assumed it would be used on a street performance truck.

According to GM Authority's sources, that will not be the case. What we'll be getting is yet another off-road spec truck, but this time it'll slot in above the Silverado Trail Boss and at the top of the line.

Despite what excitable headlines might suggest, this is not going to be a Raptor fighter. It may be playing in the same ballpark as the Ford F-150 Raptor and the Ram 1500 Rebel, but it'll be playing a different game. Instead of skipping through the dunes at high speed, the Silverado ZRX will be building on the intense trail navigating and rock crawling capability of the Colorado ZR2.

As you would expect for a serious off-road truck, Silverado ZRX will use a more robust suspension, along with DSSV dampers from MultiMatic, electronic lockers for the front and rear, and modified bumpers to improve approach and departure angles.

Power will come from the range-topping 6.2L V8 L87 EcoTec3 engine making the same 420 horsepower and 460 pound-feet of torque as it does elsewhere. Controlling that power will be GM's new 10-speed automatic transmission.

We would also expect the 3.0-liter Duramax LM2 diesel engine making 277 hp and 460 lb-ft of torque to be the entry option as it would be a good way of separating from Ford and Ram who don't offer diesel options for their off-road models. The likely timing for the ZRX entering the market will be with the facelift for the Silverado in 2022.