How to Calculate Autonomous Truck Platoon Fuel Savings
Freight operators are piloting connected and autonomous truck platoons to cut drag, smooth throttle inputs, and squeeze more work out of constrained driver pools. Translating those aerodynamic gains into defensible savings requires disciplined modelling: analysts must compare solo fuel baselines against convoy performance, blend lead and follower effects, and communicate uncertainty to finance teams. This walkthrough formalises that workflow and complements the energy resilience thinking in the microgrid black-start fuel autonomy guide so fleet depots align fuel stockpiles with platoon ramp plans.
We will define the relevant variables, derive formulas for convoy savings, and explain how to source aerodynamic reduction factors from telemetry or wind-tunnel campaigns. The resulting narrative matches the embedded calculator’s logic, allowing logistics planners to triangulate with cost benchmarks in the battery demand charge avoidance calculator when electrification and platooning strategies intersect.
Define the convoy fuel savings problem
Platooning relies on vehicle-to-vehicle communications that let followers maintain gaps under 15 metres at highway speed. The diminished aerodynamic wake for each follower reduces engine load and fuel demand. The lead truck may experience a modest benefit from reduced turbulence along its trailer, though the effect is smaller. To quantify savings, treat the convoy as a set of near-identical vehicles that would have consumed a known baseline fuel volume if they drove independently.
Savings scale with convoy size, distance, and drag-reduction percentage. They are also sensitive to payloads, crosswinds, road grades, and how tightly control systems hold the gap. Keep those caveats in mind when applying a single reduction factor across diverse routes.
Key variables and units
Collect the following inputs before running the calculation:
- fsolo – Solo fuel consumption per truck over 100 km (litres/100 km). This value should reflect fully loaded linehaul operation.
- D – Distance travelled while platooning (km). Segment multi-day trips into portions where platooning occurs.
- N – Number of trucks in the platoon (dimensionless). The minimum practical convoy contains two vehicles.
- rf – Fuel reduction percentage for each follower (percent). Obtain from wind-tunnel tests or A/B telemetry studies.
- rl – Optional reduction percentage for the lead truck (percent). Often between 0–3%.
- p – Optional diesel price per litre (USD/L) to express savings in currency.
Convert all values to consistent SI units. If onboard telematics report miles per gallon, translate to litres per 100 km using a conversions tool such as the km to miles calculator before proceeding.
Formulas for platoon savings
Use the following relationships to compute total savings:
Fuel per truck over the convoy distance: F = fsolo × (D ÷ 100)
Baseline convoy fuel without platooning: Fbaseline = N × F
Follower savings: Sf = (N − 1) × F × (rf ÷ 100)
Lead savings: Sl = F × (rl ÷ 100)
Total volume saved: S = Sf + Sl
Cost avoided: C = S × p
The formulas assume each truck would have consumed the same amount alone. If payload weights vary meaningfully within the convoy, compute F for each truck individually. Apply the same reduction percentages if the control system keeps identical gaps regardless of weight, or adjust rf for heavy loads that reduce aerodynamic sensitivity.
Step-by-step calculation workflow
Step 1: Establish the solo baseline
Derive fsolo from recent telematics covering the same tractors, trailers, and payload classes. Clean the data for idling, weather anomalies, and traffic incidents. Use median or trimmed mean values over statistically significant mileage.
Step 2: Segment the convoy distance
Identify highway stretches where the platoon remains intact. Remove urban segments or mountainous passes where platooning may be disabled. Sum the qualifying kilometres to obtain D.
Step 3: Quantify drag-reduction factors
Combine controlled testing with real-world A/B pilots. Wind-tunnel data supplies rf and rl under ideal conditions; telemetry shows how automation holds spacing under turbulence, rain, or crosswinds. Use conservative estimates when generalising beyond the pilot corridor.
Step 4: Compute baseline fuel and savings
Multiply fsolo by D ÷ 100 to obtain F. Apply the formulas to compute Sf, Sl, S, and C. The embedded calculator executes this arithmetic, formats the results, and supports optional price conversion.
Step 5: Attribute savings across stakeholders
Allocate the fuel and cost savings across fleet operators, shippers, and technology vendors according to your commercial agreements. Transparent attribution accelerates adoption and underpins contract renegotiations.
Validation and analytics hygiene
Validate the model by comparing predicted savings against weigh-station fuel receipts or engine control unit data during pilot operations. Run the calculator on multiple trips and compute the variance of S. High variance suggests that drag reductions are inconsistent, prompting reviews of spacing control logic or trailer aerodynamics.
Sensitivity analysis is essential. Increase rf and rl by 2 percentage points to reflect best-case scenarios, then decrease them by the same amount to model headwinds or rain. Adjust D down by 10% to represent platoon breakups near traffic hubs. Document the resulting savings range in governance memos.
Limitations and practical considerations
The formulas treat convoy spacing as constant, yet human-supervised or mixed autonomy convoys introduce reaction-time variability. If a human-driven truck joins mid-route, recalculate with lower rf values for that segment. Similarly, steep grades increase engine workload, altering the relationship between drag and fuel consumption; adjust fsolo using grade-specific telematics when modelling mountainous corridors.
Consider regulatory and safety constraints. Jurisdictions may cap platoon length, enforce minimum time gaps, or restrict platooning during adverse weather. Integrate those policies into dispatch planning so savings estimates remain defendable during audits.
Embed: Autonomous truck platoon fuel savings calculator
Provide solo fuel consumption, convoy distance, platoon size, and drag-reduction percentages. Add optional diesel pricing to translate the volume savings into dollars. The embedded tool returns baseline consumption, follower and lead savings, and total value.