Unlike rigs that come off the local Freightliner lot, these are tube-framed (with 3/16-inch walls), racebred machines. Think of a NASCAR Winston Cup car, only a lot bigger. Atlanta-based Elan Motorsports Technologies Group--the same company that manufactures G-Force chassis for the Indy Racing League--constructs the rolling-spec chassis for the series. Unlike its roadgoing brethren that use a solid axle, these Tonka trucks use an independent front end for ease of suspension tuning on the varied tracks.

Power is derived from the 11.1-liter Caterpillar inline-six turbodiesel that puts out 365 horsepower and 1350 pound-feet of torque in stock form. By tweaking the engine-management system, Elan can squeeze an easy 575 horsepower from the block. With a little turbo work, 1000-plus is obtainable. According to Brian Twill, STRANA's executive director, "These are probably the most durable vehicles in motorsports. Since the trucking industry builds these vehicles to withstand 120,000 miles of pulling upward of 80,000 pounds, we can use a lot of the off-the-shelf parts, and they're extremely reliable in race applications." As in Formula One, these trucks use a manumatic transmission, albeit a five-speed ZF unit that's normally found in buses.

Put the entire package on the track, and it's impressive. Till estimates 0-to-60 mph in about four seconds, and 100 comes in the mid-seven-second range. "You could probably compare these to the 'A' showroom-stock class for cars, as far as acceleration and handling," Twill says. "While those sedans aren't very dramatic taking a corner at 80 mph, our trucks will take the same corner, at the same speed, with lots of drama."