Heavy-duty efficiency is more than motor nameplate kW—it is how many kilowatt-hours you spend per mile at operating weight, speed, and grade. Use this guide to connect efficiency metrics to the range-vs-payload model in the calculator.
Benefits
- Frames kWh/mile as the bridge between battery capacity and achievable miles at fleet operating weight.
- Shows how payload and auxiliary loads (HVAC, liftgates, reefer tie-ins) move efficiency away from empty-truck lab figures.
- Supports charger sizing: daily kWh demand = miles × kWh/mile × vehicles—before demand charges and overlap peaks.
How it works
- Benchmark kWh/mile from telematics on a representative loaded week—not a single sunny demo run.
- Convert rated pack kWh and target SOC window into available energy for the shift.
- Divide by calibrated kWh/mile (or use the payload-adjusted range tool) to see if the lane fits without mid-route panic charging.
FAQ
What is a typical kWh/mile for heavy-duty EV trucks?
Urban stop-and-go and regional haul differ widely. Many fleets plan 1.5–2.5 kWh/mile for mixed duty until OEM or logged data narrows the band. Always segment by route profile and gross vehicle weight.
How does efficiency relate to payload in this tool?
Higher payload raises kWh/mile, which shortens range for the same battery. The range-vs-payload calculator expresses that relationship as percent miles lost per 100 lbs—efficiency and payload views are two sides of one energy budget.
Should I derate efficiency for winter or HVAC?
Yes. Cabin and battery thermal management can add measurable kWh/mile in cold climates. Apply a seasonal factor on top of payload-adjusted estimates when writing winter dispatch rules.
Technical specifications
- Efficiency metric: kWh consumed ÷ miles traveled (fleet-average or route-specific).
- Energy budget: usable kWh ≈ pack capacity × SOC window × pack availability factor.
- Range check: miles ≈ usable kWh ÷ kWh/mile (compare to payload-adjusted calculator output).
- Heavy-duty scope: Class 7–8 vocational and regional tractors; validate against OEM drive-cycle data.
From kWh/mile to depot demand
If each tractor averages 2.0 kWh/mile on a 180 mi shift, one truck needs roughly 360 kWh from the meter—before charging losses. Multiply by fleet size and overlap to size transformers and stagger start times. Efficiency errors compound into capex mistakes faster than range errors on a single vehicle.
Loaded efficiency vs. brochure motor efficiency
Motor and inverter efficiencies are high, but vehicle-level kWh/mile includes tyres, aero, grade, and idle auxiliaries. Heavy-duty planning should always use vehicle-level telematics at gross weight, then feed those numbers into payload and range tools for lane approval.