PIB TIP: FIXED AND VARIABLE COSTS. A fixed cost is determined and does not change from month to month. Any expense related to time, such as a tractor payment, insurance payment, permit and license fees, is a fixed cost. That cost will be the same every day whether your truck is driven one mile or 600 miles. A variable cost – such as fuel, tires and maintenance – is related to how much you drive. Most variable costs remain the same for every mile you run. The Partners in Business program is produced by Overdrive and the consultants at ATBS, the nation’s largest owner-operator business services firm, and is sponsored by Schneider National Inc. and Freightliner Trucks.