A truck that isn't moving is still costing you. Here's how to calculate the true downtime cost and where the biggest hits hide.
Most fleets count repair cost as the cost of breakdown. The repair is usually the smallest piece.
Daily downtime cost = (Daily revenue) + (Daily fixed cost) + (Driver wages if paid) + (Repair + towing + emergency parts markup). Most fleets underestimate by 40% because they ignore fixed cost accrual and driver pay.
Tractor down 3 days for a DPF replacement: lost revenue $3,600 + fixed cost $180 + driver pay $660 + repair $4,200 + tow $1,200 = ~$9,840 total. The repair invoice ($4,200) is only 43% of the real hit.
Three levers: shorten MTTR (mean time to repair) with telematics + OEM parts pre-staging, prevent the breakdown via PM, and stage spare tractors at >25-unit fleets for instant swaps.
ATRI puts the average roadside event at $334 in direct repair, but total cost including lost revenue and fixed accruals typically runs $1,500–$3,000+ per day off the road.
1) Aggressive PM, 2) telematics for early fault detection, 3) parts pre-staging at top dealers, 4) spare tractors at scale.