Calculator 01 / Fuel & Fluids
Fuel & Fluids Calculator
Trip fuel cost, DEF consumption, and coolant mix ratio — three quick fluid calculations in one place.
How this calculator works
DEF (Diesel Exhaust Fluid) dosing rate varies by engine, duty cycle, and how hard the truck is worked — 2–3% of diesel volume is a commonly cited working range for modern SCR-equipped diesels, so treat this as a planning estimate rather than an exact figure for your specific engine. Coolant mix ratio follows standard antifreeze/water dilution — a 50/50 mix is the typical factory default, with higher coolant percentages used for extreme cold climates up to a manufacturer-specified maximum (usually around 70%, since pure antifreeze actually transfers heat worse than a proper mix).
Why not just run 100% coolant for maximum protection?
Pure antifreeze has worse heat transfer and freeze protection than a proper water/coolant mix — most manufacturers cap the recommended concentration around 60–70% coolant even in extreme cold.
Does DEF consumption really scale directly with diesel usage?
Roughly, yes, for planning purposes — actual DEF consumption depends on engine load, aftertreatment system, and duty cycle, so treat the percentage as an estimate and track actual usage over time for a more precise number.
Why does 2-stroke mix ratio matter so much?
Too little oil and the engine runs without enough lubrication, risking piston and bearing damage; too much oil fouls spark plugs and increases smoke and carbon buildup. Always match the ratio to your specific engine manufacturer's spec, not just what's common.
Estimates only. Confirm DEF dosing behavior and coolant mix limits against your specific engine or vehicle manufacturer's documentation.