AUSTIN, TX – It would seem silly to pack a 420-hp, 6.4L V-8 engine into a fullsize SUV and tell drivers they can rev up to speeds more than twice the legal limit in most states.

In the right hands, however, such a vehicle can maintain a calm demeanor in everyday driving but be ready to pounce when provoked. That appears to be the philosophy with the all-new SRT version of the ’14 Jeep Grand Cherokee.

Once a trim package but now Chrysler’s performance brand, SRT is a key strategy to retaining the auto maker’s muscle-car loyalists. It’s no surprise then that some executives tout SRT’s significance among Baby Boomers, who not only can afford performance vehicles but also have the same lust for such a vehicle as when they were 16.

Where once there were few players in the luxury SUV field, today the market is crowded with offerings from Mercedes-Benz, Audi, BMW, Lexus and Porsche. Combined, they offer a small but lucrative performance segment that, in addition to Jeep’s new entry, includes the Porsche Cayenne GTS, BMW X5 M and Mercedes GL63 AMG.

At a media launch of its volume-model Jeep Grand Cherokee, Chrysler invites journalists to sample the more-powerful SRT version at the Circuit of the Americas race track here.

Aside from its 20-in. aluminum rims painted brilliant black, the SRT Grand Cherokee carries a more aggressive front end with black accents that sets it apart from lower-priced Jeeps.

Inside, drivers are treated to a silken black interior with an even mix of chrome and carbon-fiber trim lining the center console and dash. A sepia-toned interior also is available. There are ample reminders that this is an SRT-tuned product, with the performance-brand’s logo embossed on the front seats, the hubs and, as a Chrysler first, the steering wheel.

In the past, SRT-tuned vehicles carried the originating brand on the steering wheel; the move here is another step toward establishing SRT’s stand-alone presence.

Lower-level Grand Cherokees have sport, tow and snow driving modes. The SRT offers these as well but adds an exclusive “track” mode that switches to a sportier suspension and handling. Torque distribution moves 30% of the power to the front axle and 70% to the rear, compared with an even split in tow and snow modes and a 60/40 rear-front division in auto mode.

A launch-control function, which has a lighted button resembling the yellow-green-red illumination at a drag strip’s starting line, allows a driver to set up engine, transmission, stability control and suspension for a track-ready launch. Unless you want a speeding ticket, that’s reserved for closed-circuit racing only.

Surprisingly, the SRT offers an Eco mode for fuel conservation, although it does not appear to affect performance. The SUV is rated for 13 mpg (18 L/100 km) city/19 mpg (12 L/100 km) highway, expected numbers for a vehicle in its class.

The SRT Jeep Grand Cherokee for the first time employs an 8-speed automatic transmission that makes for an easy ride, and the engine is noticeably quiet at idle. The well-insulated interior keeps outside noise at a minimum as well.

Upshifting with paddles or in auto mode is quick and easy with the 8-speed. Rowing through the gears – in both directions – is extremely smooth.

The accelerator is a bit heavy and steering can become a workout for this heavier model, but the sport suspension in all modes makes for an exciting experience even on the dullest of roads, especially when it comes to passing.

However, the race track is the place where the SRT really flexes its muscle. You know it’s helmet time when the big SUV begins whipping around the 3.4-mile (5.5 km) track at 120 mph (193 km/h) on a surface replete with 20 turns and far fewer straightaways.

Hearing the engines roar and tires squeal reminds us of a NASCAR mash-up, but whether seated behind the wheel or on the passenger side, it can send your heart tumbling to your toes. Surprisingly, bodyroll remains at a minimum, even around the tightest curves.

Tough Brembo disc brakes – 15 in. (38 cm) in the front and 13-in. 33 cm) in the rear – effortlessly curb the SUV’s forward trajectory. The engine is hot and the stench of burnt rubber abounds, but this powerful Jeep under track conditions not only stays on its feet but looks good doing it.

The SRT Grand Cherokee starts at $62,995, climbing to $64,885 with options, a steal compared with Chrysler’s SRT Viper and other comparable models.

Jeep and SRT have found a winning combination by taming the wild beast without rendering it lifeless. If this is the next phase for the Grand Cherokee – striking looks with muscle under the hood – then let the hunt begin.

afoley@wardsauto.com

'14 Jeep Grand Cherokee SRT
Vehicle type Four-door, 5-passenger, 4-wheel-drive sport-utility vehicle
Engine 6.4L Hemi OHV V-8; iron block/aluminum heads
Power 470 hp @ 6,000 rpm
Torque 465 lb.-ft. (630 Nm) @ 4,300 rpm
Bore x stroke (mm) 103.9 x 94.5
Compression ratio 10:9:1
Transmission 8-speed automatic
Wheelbase 114.8 ins. (292 cm)
Overall length 191.3 ins. (486 cm)
Overall width 77.1 ins. (196 cm)
Overall height 69.1 ins. (176 cm)
Curb weight 5,150 lbs. (2,336 kg)
Base price $62,995
Fuel economy 13/19 mpg city/highway
Competition Porsche Cayenne GTS, BMW X5 M
Pros Cons
Fantastic eco mode Still a gas guzzler
Exciting on the track Heavy off the line elsewhere
A steal in its price range Other competitors can be tempting