Circuit of the Americas in Austin, Texas is a serious race track that will host Formula One, MotoGP and Pirelli World Challenge events this year. The 20-turn, 3.41-mile road course's high-speed esses, long back straight, heavy brake zones and tight hairpins are a thorough workout for race cars and high-performance road cars alike, and here I am, tackling it in an SUV. But not just any SUV -- the 2018 Alfa Romeo Stelvio Quadrifoglio.

The idea of wrestling a 4,360-pound crossover around a challenging circuit doesn't seem ideal in the beginning, but after a three-lap run in the super Stelvio, any doubt is extinguished. With "Race" mode engaged -- and no electronic nannies holding me back -- the Quadrifoglio is a delightful terror. Through the esses, side-to-side weight transitions are handled with aplomb. Turn in is nearly immediate with gobs of steering feedback through the wheel.

Around corners, there's massive stick from the 20-inch Pirelli P Zero tires and the adaptive suspension only gives way to a touch of body roll. The torque vectoring rear differential does a fine job of swinging the tail around for tight maneuvering. But for the really tight stuff, trail braking helps rotate the back around, too. Of course, bomb too hot into a hairpin and the Stelvio's front grip falls off, gradually giving you ample time to make corrections and continue on your way.

Powering out of bends and down the straights is no problem, thanks to the Quadrifoglio's 2.9-liter twin-turbocharged V6 and its 505 horsepower and 443 pound-feet of torque, accompanied by magnificent noises courtesy of the performance exhaust. Alfa's most powerful production engine to date works with a slick-shifting eight-speed ZF automatic transmission to route power to all four wheels, and Alfa says you can storm to 60 mph in just 3.6 seconds. Manual shift response via the aluminum steering column-mounted paddle shifters is excellent, but shift mapping in full auto is so well-tuned that, on the track, I let the computer do the work.

Get a good run out of Turn 11 and you'll see 140 mph down the back straight by the time you get to the brake point. Stepping hard on the left pedal causes the Stelvio to dance a little as the weight transfers to the front, but the optional $8,000 Brembo carbon ceramic brakes briskly kill speed in preparation for the sharp left-hander ahead. A smoother initial brake input before dialing in full clamping muscle from the six-piston front and four-piston rear calipers helps settle things on subsequent trips through the heavy brake zone.

Yes, on track, the Quadrifoglio is simply fantastic. Capable, balanced and forgiving, but most impressively engaging from behind the wheel when strapped into the available $3,500 Sparco carbon fiber bucket seats. It's perfectly respectable on public roads, too. The Stelvio's "Natural" drive setting brings a docile experience. The engine and transmission operate smoothly when light footing it around town. Suspension damping is fine enough for a comfortable ride on smooth Texas pavement, but it'll likely be a different story back home on broken Midwest roads.

It's inside the cabin where flaws present themselves. The standard leather and Alcantara seats, flat-bottom steering wheel, carbon fiber trim and leather-wrapped door panel and dash tops are all perfectly nice, but the hard plastics making up much of the major surfaces and hollow buttons and knobs are seriously disappointing. What's more, a ton of road and wind noise makes its way into the cabin from the B-pillar area. At one point, I actually thought the windows were down.

The 8.8-inch infotainment system features navigation, a 14-speaker Harman/Kardon sound system and Bluetooth, but the simple screens and just OK interface aren't anything to write home about. Working through menus with the rotary controller on the center console isn't overly complicated, but the system lacks the intuitiveness and refinement of similar setups from Audi, BMW and Mercedes-Benz.  For those who don't want to bother learning the Alfa system, both Apple CarPlay and Android Auto integration are standard, which is good.

For safety, blind-spot monitoring, park sensors, backup camera and rear cross traffic alert are included on every Quadrifoglio. Pony up an additional $1,500 and you'll get a serviceable adaptive cruise control system with stop and go, forward collision warning, lane departure warning and automatic high beam headlights. Sadly, a 360-degree camera isn't offered.

Visually, the Quadrifoglio is a head-turner. Bigger front air intake openings help differentiate it from lesser Stelvios, as do the model-specific grille, hood vents, four-leaf clover badges, rocker panels, quad exhaust tips and 20-inch wheels.

The Stelvio Quadrifoglio will trickle into dealers starting in April, with a base price tag of $81,590, including $1,595 for destination. That's a substantial price premium over the base Stelvio's $42,990, but then again, the Quadrifoglio packs a much more substantial performance punch.

As for the cabin shortcomings, I personally am willing to overlook them because of how incredible the Quadrifoglio is to drive on both road and track. Future owners should definitely make it a point to do some track days. Mercedes and Porsche will sell you similar SUVs with amazing performance credentials and nicer interior materials, but trust me, you'll have more fun in the Alfa.