About

For logistics managers, fuel is only part of the equation. A comprehensive Cost Per Mile (CPM) or Kilometer (CPK) analysis must include fluid consumables: Engine Oil, Transmission Fluid, Differential Oil, and AdBlue (DEF). While fuel is purchased daily, lubricants are long-term consumables that are often overlooked in spot-pricing calculations, leading to margin erosion.

This calculator integrates the "Lubricant Factor"-typically 1% to 3% of fuel costs depending on the age of the fleet-into the standard trip cost logic. It allows fleet operators to input specific drain intervals (km) and sump capacities (L) to derive a precise micro-cost per kilometer.

Formulas

Total Cost is the sum of fuel cost plus the amortized cost of lubricants over the distance.

1. Fuel Cost (C_fuel):

C_fuel = Dist100 × Cons × Price_fuel

2. Lubricant Amortization (C_lube):

Capacity × Price_oilInterval × Dist

3. Total Cost per km (CPK):

CPK = Total CostDist

Reference Data

Fluid Type	Avg Consumption (Heavy Truck)	Change Interval	Approx. Cost Impact
Diesel Fuel	30 - 40 L/100km	Daily	60% of OpEx
AdBlue (DEF)	4% - 6% of Fuel Vol.	Daily	3% of OpEx
Engine Oil	0.2% of Fuel Vol.	40,000 km	1% of OpEx
Gearbox Oil	Low	200,000 km	0.2% of OpEx
Coolant	Low	Annual	0.1% of OpEx
Grease	0.5 kg/month	Weekly	Negligible

Frequently Asked Questions

AdBlue (Diesel Exhaust Fluid) is required for modern diesel engines to reduce NOx emissions. It is consumed at a rate of roughly 4-6% of your diesel consumption. Ignoring this adds up to a significant hidden cost.

There are two types: "Burn-off" (oil lost during operation) and "Service Fill" (oil replaced during maintenance). This tool calculates the "Service Fill" cost amortized over the service interval (e.g., cost of 40L oil spread over 40,000km).

Yes, this tool uses your browser's local storage to remember your last inputs for Fuel Consumption and Oil Capacity, so you don't need to re-enter specs for the same vehicle.

No. This calculator focuses strictly on fluid power and lubrication. Tire wear, driver wages, and depreciation are separate fixed/variable costs not covered here.