Running approximately 8.5 lb of boost, the twin-turbo 4.2 has given up none of its normal smoothness and quiet. Except for that unexpectedly quick climb made by the speedo needle, some turbo whoosh, and a bit of rear squat at launch, things inside during acceleration runs remain quite unremarkable. With the all-wheel-drive system to maximize grip, there's virtually none of the tire slip, yaw, or torque steer of typical high-performance machines. This development vehicle's benign overall behavior strongly reminds us of the old turbo V-6 GMC Typhoon/Cyclone. Indeed, a post-run look at our laptop revealed a steep acceleration curve and consistent mid-5-sec runs to 60 mph, with a best run of 5.35. That's compared to 8.2 for the standard TrailBlazer. Somewhat disappointing, but probably wise, is a software bug intentionally left in the engine's computer that limits top speed to 110 mph. Otherwise, no letdowns.

The handling/braking upgrades are nicely matched to the newfound power. For example, the beefier brakes and more aggressive rolling stock shortened the production TrailBlazer's 132-ft 60-0 stopping distance by 12 ft. These improvements also conspire to add an impressive 5 mph to the TrailBlazer's pass through the high-speed slalom and helped generate 0.86 g on the skidpad. These numbers put it squarely in BMW X5 territory. Handling at high speeds is largely neutral with initial push and tail-out available under full throttle. Overall, we'd say it's a smart chassis setup by LeDuc and company and a nice complement to the 400 horses underhood.

Want one? Send your cards and letters to GM. Though many have wondered about the marketplace viability of high-performance sport/utilities, the demand appears to be there: Last year, the ML55 AMG was the best-selling among all AMG-ified Mercedes-Benzes. BMW is just now coming to market with its own hi-po, though not M-badged, X5. Let's not forget the upcoming Porsche Cayenne. So, why not a 400-hp TrailBlazer?

Chevrolet TrailBlazer Twin-Turbo Concept
GENERAL
Location of final assemblyMoraine, OH
Body style 4-door, 5 pass
EPA size classSpecial purpose
Drivetrain layoutFront engine, 4WD
AirbagsDual
POWERTRAIN
Engine typeI-6 twin turbos & intercooler, alum block & head
Bore x stroke, in3.66 x 4.01
Displacement, cu in/L256/4.2
Compression ratio10.1:1
Valve gearDOHC; 4-valves/cyl
Fuel inductionSFI
Horsepower, hp @ rpm400 @ 5200
SAE torque, lb-ft @ rpm (est)400 @ 2500
Transmission type4L65-E
1st3.06:1
2nd1.63:1
3rd1.00:1
4th0.70:1
Reverse2.29:1
Axle ratio3.73:1
Final drive ratio2.61:1
Recommended fuelUnleaded premium
DIMENSIONS/CAPACITIES
Wheelbase, in113.0
Length, in191.6
Width, in74.7
Height, in71.9
Track, f/r, in64.1/63.1
Headroom, f/r, in40.2/39.6
Legroom, f/r, in43.1/37.1
Shoulder room, f/m/r, in58.5/58.5
Ground clearance, in6.0
Base curb weight, lb4645
Payload capacity, lb1150
GVWR, lb 5700
GCWR, lb11,000
Towing capacity, lb 6200
Cargo Capacity, cu ft80.1
Fuel capacity, gal 18.7
CHASSIS
Suspension, f/r IFS, Double A-arm, coil springs/live axle, five-link, coil springs
Steering typeHydraulic assist, rack & pinion
Ratio 20.4:1
Turns, lock to lock3.1
Turning circle, ft36.9
Brakes, f/r12.0-in vented discs/12.8-in vented discs
Wheels18x9.5 alloy
TiresBFGoodrich Comp T/As 295/45ZR18
PERFORMANCE
Acceleration, sec, 0-605.35
Standing quarter mile, sec/mph13.91/97.40
Braking 60-0, ft120
Speed through 600-ft slalom, mph61.1
EPA fuel economy, city/hwy 14/20 (est)
PRICE
Base price $32,495
Price as tested (est)$47,000