All it takes is a peek under the hood of the Hellcat-powered Jeep Grand Cherokee Trackhawk to know that it’s one of the fastest ways to take the kids to soccer practice in 2018. But just how fast? About 175 mph, according to a recent test run conducted by Hennessey Performance.
Amidst exorcising Demons and giving Ford Raptors a third axle last year, the Texas-based performance shop also made plans to turn the Trackhawk into a legendary bird of thunder. Not satisfied with the 707 horsepower on tap from the 6.2-liter supercharged Hellcat engine, Hennessey unveiled plans for an HPE1000 upgrade designed to boost it to 1,012 horsepower and 969 lb-ft of torque.
We had our own fun with the Trackhawk’s launch control system, which is capable of rocketing the mega-SUV from 0 to 60 mph in an eye-watering 3.5 seconds, when our Lawrence Ulrich reviewed it back in October. But Hennessey needed to go a little further with the stock model before testing out its upgrades—specifically, the shop wanted to determine the Trackhawk’s true top speed.
Jeep claims the truck is capable of 180 mph, which no publication has gotten the chance to verify yet. But a quick blast on Hennessey’s runway shows that the stock Hellcat “only” has enough fire in its belly to push it to 175 MPH, after which it appears the laws of aerodynamics begin to finally take effect. The ZF eight-speed automatic transmission also seems to acquit itself well, holding shifts until just past the redline.
John Hennessey himself reports the vehicle is “completely stable” at the limit, though you can see the temperature gauge climb noticeably over the course of the run. It also doesn’t seem like 180 is possible, at least without a few more miles to run, as it took a full fifteen seconds to get from 170 to 175 mph—the equivalent of nearly three-quarters of a mile at those speeds.
It’s easy to laugh off the Jeep Grand Cherokee Trackhawk as a ridiculous, brutish thing, but the way the Hellcat motor is able to overcome the sheer weight and drag of a full-size SUV and push it to those speeds is undeniably impressive. See, kids: Science doesn’t have to be boring.