Big fun at track, and pretty nice on the highway, too.

Zero to 60 in 4.8 seconds. Sounds about right for a Shelby GT, but a 5,000-pound SUV? And a Jeep?

Yep, the next generation of SRT goodness has arrived for model year 2012, and included in the mix along with the Dodge retro muscle-cars is the WK2 Grand Cherokee SRT8, which gets the new 470 hp 6.4L V-8. The 392ci OHV engine (yep, it’s a pushrod motor) also delivers 465 lb-ft of torque at 4,300 rpm, with 90 percent of that available at 2,800. Top rated speed is 160 mph, and tow rating is 5,000 pounds. Backing the engine is the W5A580 five-speed automatic and Magna MP3010 full-time single-speed transfer case, which transfers torque front to rear at rates varying from 50/50 to 35/65, depending on conditions and drive mode.

One of the coolest features of the new SRT is the “Selec-Track” adaptive suspension system, which utilizes five different drive-mode settings---Auto, Sport, Track, Snow and Tow---to readjust things like torque proportioning, throttle control, cylinder deactivation and shock valving on the fly. This really allows you to fine-tune the vehicle’s handling characteristics, to optimize mileage, and to get power most efficiently to the 45-series Pirelli P-Zero all-season tires on 20-inch five-spoke aluminum rims.

No, we didn’t wheel it---SRT Grands don’t have a low-range gear, and you can’t raise the suspension with this model, though ti does have the electronic rear brake limited-slip---but we did get a chance to whomp it around some hot laps at the Big Track at Willow Springs Raceway earlier this week (the verdict: When it comes to racing, we suck. The vehicle doesn’t), and the Grand was a truckload of fun to drive. With the adaptive suspension set on its stiffest setting (“Track” mode) and the stability control disabled (thank goodness for that option), the SRT8 Grand Cherokee had no trouble keeping up with the (equally-powerful-but-much-lighter-in-weight) Chargers and Challengers that were clogging up the track and preventing us from lapping the competition. (Okay, we made that up.) The Pirelli P-Zeros and 15-inch Brembo six-piston brakes proved their worth in and out of the corners, with great adhesion, predictable grab and progressive pedal feel. We didn’t get it to 160 mph, but 130 on the straights was easy to achieve, with plenty of power to spare. Away from the track, the SRT is a soothing respite to the bustle of noisy city traffic---quite nicely soundproofed, luxuriously appointed, and a pleasure to drive.

As you might imagine, the SRT8 is stuffed with all sorts of creature-comfort goodies, with awesomely firm Nappa leather-and-suede seats, leather wrapped steering wheel with paddle-shifters, carbon-fiber accents on the instrument panel and door trim, onboard entertainment system and, as an option, an 825-watt, 19-speaker (!) Harman-Kardon surround-sound stereo with GreenEdge speaker and amplifier technology, which increases the system’s efficiency while trimming weight.

Starting at a base price of $54,470, the new Jeep should available at your local Jeep dealer within the next couple of weeks. For what you get, it’s a lot of vehicle for the money, and one that we could see ourselves soaking up many long-distance highway miles in. Racing, on the other hand . . . well, we think we’ll stick to rock crawling in the future.