A giant 170 ton production truck donated by Hibbing Taconite in 1998 was originally purchased in 1975 for $451,900 and operated for 110,000 hours, the equivalent of 12.5 continuous years. During the career of Truck 166 it hauled over 30 million tons of ore and waste. Considered an electric haulage unit, it used electric drive motors in each of its four wheel hubs, powered by a 16 cylinder, 1600 horsepower General Motors diesel engine. Its top speed was 32 mph, its fuel tank held 800 gallons, and its wheels were 4.25 feet in diameter with tires 10.5 feet in diameter, requiring 162 revolutions to travel a mile. During its working life, the tires cost $7,500 each, or $60,000 for a complete set of eight, and despite their 50 ply construction and tread depth of more than 3 inches, sharp taconite fragments could puncture them. The radiator held about 150 gallons of coolant, the box held nearly half a million one pound packages of butter by volume, and the maximum gross vehicle weight was rated at 630,000 pounds. Drivers often compared handling these monster trucks from a seat 18 feet above the ground to driving a two story house.