Steve Hartsell, regular driver of the medium-duty truck I'm currently driving, smirks as I take it slightly off course. "You're gonna curb it," he says. Hartsell drives for the Pratt & Miller Corvette C6R racing team, whose Vettes won the GT1 class in the 24 Hours of Le Mans sports-car race in 2002, 2003, and 2005 and are the reigning American Le Mans Series GT1 champs.

"Do you think?" I ask optimistically, peering furiously in the right side mirror of the Chevrolet Kodiak 4500 as we round a corner.

"Oh, yeah," says the experienced Hartsell.

"No, I think...dammit!" I ease around the tight right turn, still getting a feel for how wide you have to swing the tow vehicle around a corner when hauling a 45-foot, 32,000-pound gooseneck trailer with a medium-duty truck. This Kodiak tow vehicle was outfitted by Monroe Truck Equipment, which installs air suspension equipment, including rear springs and mounts on the cab and seat to cushion driver punishment. All this isolation gives you a waterbed effect, but you quickly adapt.

The Link Manufacturing-supplied UltraRide air suspension replaces the rear leaf springs with air springs mounted to large trailing arms. This not only yields a better ride, but lowers the ride height by three inches at the axle, making the Kodiak's pickup bed low enough to hitch a gooseneck or fifth-wheel trailer without tipping the front up in the air. The air suspension also lets the truck "kneel" down lower for hitching to the trailer.

Under the hood of the 2006 truck is the Duramax 6600 turbodiesel V-8, rated at 300 horsepower and 520 pound-feet of torque. Hartsell says it feels like the Kodiak is a little more sluggish than the team's usual one-ton dualie with the Duramax, probably a result of the dualie's lower weight and lower effective gearing because of the smaller diameter wheels and tires. For 2007, the Kodiak is available with an optional upgraded engine with the same horsepower, but 605 pound-feet of torque. It should drink less #2 diesel, because the Allison automatic gains another gear for a total of six speeds.

The Monroe Kodiak pickup is towing Pratt & Miller's trailer that carries the team's spare parts, pit-lane equipment, and hospitality items. The team's pair of Kenworth highway tractors pull the glittering, polished aluminum 57-foot trailers, each dedicated to carrying one of the team's racers and its related garage tools and equipment. For obvious reasons, the team won't let journalists drive the big-rig carrying the almost-irreplaceable race cars, those each get their own Kenworth rig, leaving me instead to try my hand with the truck that hauls spare parts and pit equipment. And the medium-duty doesn't require a commercial driver's license.