I had a Sterling class 8 stretched with a 22 ft box on it. C15 6nz Caterpillar, 44 locking rears, 18k front axle, 400 gallon fuel capacity, 3 stage, 18 gauges, dual stacks, it was the wrong truck to make into a 10 wheeler. 28,500# empty. But, oh, how fun it was to drive. It would pass...