2011 Chevrolet Silverado 1500 Regular Cab Owner's Manual - Page 403

Driving and Operating In order to calculate the amount of weight any front accessory, such as a snow plow, is adding to the front axle, use the following formula: 9-119 For example, adding a 318 kg (700 lb) snow plow actually adds more than 318 kg (700 lb) to the front axle. Using the formula, if the snow plow is 122 cm (4 ft) in front of the front axle and the wheel base is 305 cm (10 ft), then: W = 318 kg (700 lb) A = 122 cm (4 ft) W.B. = 305 cm (10 ft) (W x (A + W.B.))/W.B. = (318 x (122 + 305))/305 = 445 kg (980 lbs) So, if the front axle reserve capacity is more than 445 kg (980 lbs), the snow plow could be added without exceeding the front GAWR. Heavier equipment can be added on the front of the vehicle if it is compensated for by carrying fewer passengers, less cargo, or by positioning cargo toward the rear. United States (W x (A + W.B.)) /W.B.= Weight the accessory is adding to the front axle. Where: W = Weight of added accessory A = Distance that the accessory is in front of the front axle W.B. = Vehicle Wheelbase Canada