Fleet operators often compare diesel, CNG, LNG, propane autogas, and battery electric vehicles when fuel prices, emissions targets, grants, maintenance issues, or route requirements change. The comparison is only useful when the units and sources are clear. CNG quotes are commonly in gasoline gallon equivalent (GGE), LNG comparisons often use diesel gallon equivalent (DGE), propane is commonly billed by the gallon, and electricity depends on the tariff, demand charge, and charging schedule.
This guide explains how to build a source-aware first-pass screen. It is meant to identify which assumptions need local validation before a fleet makes procurement, infrastructure, emissions, tax, grant, or operational decisions.
Why Evaluate Alternative Fuels Now
Alternative fuels can be worth evaluating when fuel prices, maintenance costs, emissions goals, grant opportunities, regulations, or route requirements change. Those inputs are date and location dependent, so a defensible screen starts with current source data instead of national averages alone.
Use 12 months of telematics, fuel-card records, maintenance work orders, route profiles, payload data, and depot dwell time. Then add dated supplier quotes, utility tariff and demand-charge estimates, infrastructure quotes, and any grant or incentive documents. Regulations and incentives can change quickly, so treat them as items to verify rather than permanent assumptions.
The goal is not to pick a universal winning fuel. The goal is to identify which vehicle classes and routes deserve deeper engineering, utility, emissions, tax, grant, and procurement review.
Start your evaluation with 12 months of actual fleet telematics data: daily miles driven, idle time, fuel consumption, and return-to-base patterns. This data determines which vehicles are candidates for which fuel types and prevents over- or under-sizing infrastructure.
Fleet Fuel Comparison Calculator
Compare total cost of ownership for fleet vehicles across diesel, CNG, LNG, propane, and battery electric including infrastructure, maintenance, and emissions.
Compressed Natural Gas (CNG) and Liquefied Natural Gas (LNG)
CNG and LNG are both natural gas fuels, but they are not priced the same way in this screen. CNG is entered in dollars per gasoline gallon equivalent (GGE), which matches common AFDC and retail reporting. LNG remains on a diesel gallon equivalent (DGE) basis. Verify the unit on every supplier quote before comparing cost per mile.
CNG is usually evaluated for return-to-base routes where tank volume, payload, fueling window, station access, and cylinder inspection can be managed. LNG may be evaluated for heavier or longer-range routes, but it adds cryogenic handling, boil-off, station availability, and supplier-contract questions.
Natural gas vehicle suitability still depends on current OEM availability, engine certification, duty cycle, maintenance capability, fueling reliability, tax and fee treatment, and local air-quality or grant program rules. The guide and app do not approve a conversion or infrastructure design.
Renewable natural gas claims require contract documentation and the selected accounting program. The app does not assume LCFS, RFS/RIN, carbon-negative, or offset treatment from a fuel label alone.
Propane Autogas
Propane autogas is entered in gallons, not DGE or GGE. The app uses a local 0.66 DGE per gallon planning conversion so cost and consumption are visible, but users should verify vehicle efficiency and supplier billing against AFDC data, OEM data, and local contracts.
Propane can be a practical candidate for some light and medium-duty return-to-base fleets where vehicle offerings, fueling logistics, and supplier support fit the route. Infrastructure can be simpler than CNG or high-power electric charging, but tank, dispenser, code, lease, maintenance, and inspection terms still need local review.
Emissions, maintenance, and cost differences vary by platform and duty cycle. Treat any generic propane advantage as a hypothesis until it is checked against current vehicle data, fuel price, route records, and reporting boundary.
Propane can be a lower-complexity pilot fuel for some fleets, but the pilot should still include supplier contract review, tank/dispenser code review, driver training, maintenance planning, and current grant or incentive checks.
Battery Electric Fleet Vehicles
Battery electric fleet vehicles can reduce tailpipe emissions and shift operating cost toward electricity tariffs, demand charges, charger maintenance, and utility infrastructure. The business case depends on route length, dwell time, payload, climate, charging strategy, service upgrade timing, and charger reliability.
Do not use a single blended electricity rate if demand charges, time-of-use windows, managed charging, or depot peak limits materially affect the project. Request a utility service study and tariff review before treating charger cost or energy cost as settled.
Vehicle range, battery degradation, payload, winter and summer performance, charger uptime, warranty limits, and replacement planning must be checked against the specific OEM platform and route data.
Request a utility service study before committing to a BEV fleet deployment. Service upgrades, transformer capacity, switchgear, charger networking, demand management, and construction lead time can dominate the schedule and cost.
Emissions Comparison Across Fuel Types
Emissions comparisons depend on the boundary. Tailpipe, tank-to-wheel, well-to-wheel, Scope 1, Scope 2, LCFS, RIN, REC, renewable fuel, and grant accounting can produce different answers for the same fleet. Name the boundary before comparing fuels.
The app uses simplified fuel CO2 factors and an editable grid kg CO2/kWh factor. That is useful for a planning screen, but it is not a formal inventory, lifecycle model, credit calculation, or regulatory submittal.
For formal work, select the current protocol and source data first: EPA emissions factors, eGRID or utility-specific electricity factors, approved lifecycle models where applicable, fuel contracts or certificates, activity records, and qualified emissions review.
When comparing emissions, always specify whether you are using tailpipe, tank-to-wheel, or well-to-wheel figures. The choice of boundary can change the ranking of fuel options significantly, especially for electric vehicles where upstream generation emissions vary widely.
Fueling Infrastructure Costs and Planning
Infrastructure cost is site-specific. Treat any national or vendor example as an order-of-magnitude placeholder until the project has local vendor quotes, utility service study, permitting feedback, AHJ requirements, insurance review, maintenance staffing, and schedule risk.
CNG projects need gas service, compression, storage, dispensing design, safety systems, maintenance, and inspection planning. Propane projects need tank and dispenser siting, supplier terms, code review, and operations planning. Electric projects need charger selection, utility make-ready, demand management, electrical protection, networking, uptime, and service agreements.
Include downtime, training, spare vehicles, parts availability, fueling or charging queues, and phased expansion costs. Infrastructure amortization can dominate the result when vehicle count or annual miles are low.
Grant and incentive programs are date-specific and competitive. Check the current AFDC incentives database, program pages, tax guidance, state or utility rules, and award documents before entering any offset.
Phased Conversion Strategy
A phased conversion limits operating risk and keeps assumptions testable. Start with vehicles that return to base, have predictable mileage, and can tolerate the fueling or charging window. Compare measured energy use, maintenance, range reserve, downtime, driver feedback, and infrastructure performance against the planning assumptions.
Use each phase to update the model with real data. Keep conventional-fuel backup or contingency options until the alternative system has proven reliable through seasonal conditions, maintenance cycles, and unusual route demand.
Do not scale infrastructure or commit replacement schedules faster than utility, vendor, maintenance, grant, budget, and operations teams can support. The practical output of the guide is a review list, not a mandate to convert an entire fleet.
Before expanding a pilot, document the observed route fit, actual fuel or kWh per mile, queue time, maintenance events, driver training issues, utility or station uptime, and any grant or reporting obligations.