Ford's 2008 F-450 Super Duty — the first factory-built Class 4 pickup — can tow 24,500 pounds (8,000 pounds more than the nearest competitor) and is powered by a new, more powerful 6.4-liter Ford diesel engine. The new Super Duty also features a unique TailGate Step that folds down to make it easier to load heavy equipment in the bed; and PowerScope power-folding, power-telescoping trailer-tow side mirrors. Estimated list price range: $23,000 to $65,000.