Fleet fuel savings calculator
How many gallons and dollars a fleet saves in a year from a better average mpg and from cutting idle hours, per vehicle and across the fleet.
Your numbers
FleetBetter mpgLess idling See your resultResult
Saved per year $54,11914,242 gallons across 25 vehicles From better mpg 8,242 gal329.7 gal per vehicle From less idling 6,000 gal240.0 gal per vehicle Per vehicle $2,165 Stop working this out by handFleetZap fuel logs track gallons and cost per vehicle, and GPS Tracking brings in engine hours automatically, so you can see fuel economy change over time.
See FleetZap Maintenance · Try the demoThe formula
Gallons saved = Miles ÷ mpg now − Miles ÷ mpg after + Idle hours cut × Fuel per idle hour
With the example: 30,000 ÷ 6.5 − 30,000 ÷ 7 = 330 gallons a vehicle from mpg, plus 300 h × 0.8 = 240 from idling, so about 14,240 gallons and $54,100 a year across 25 vehicles. Half an mpg matters more on a truck that does 6 than on a car that does 30. The idle time guide covers where the idle hours come from.
Using the numberWhat to do with it
- Measure first: real mpg from fuel logs and real idle hours from telematics, so the saving is something you can check later.
- Tire pressure, alignment and air filters are maintenance items with a direct mpg effect; keep them on the PM schedule.
- Idling also adds engine hours, which brings hour-based services sooner.
Guides behind this calculator
Reducing idle time Fleet fuel management Fuel cards and fuel softwareMore free calculators
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The heart of FleetZap, and everything a maintenance team needs in one place: work orders and preventive maintenance, inspections and the field app, plus a parts store with purchasing, compliance and certificate tracking, multi-location assets with a full lifecycle, and the KPIs that prove it’s working.
- Work orders
- Preventive maintenance
- Procedures, inspections & field app
- Parts & purchasing
- Compliance
- Assets, reports & KPIs
Good to know
How do you calculate fuel savings from better mpg?Gallons saved = miles ÷ old mpg − miles ÷ new mpg. On 30,000 miles, going from 6.5 to 7 mpg saves about 330 gallons.
How much fuel does idling use?It depends on the engine and load. Read it from your telematics or the engine maker's data rather than a general figure, since it varies widely.
What saves the most fuel in a fleet?Usually less idling, steady speeds, correct tire pressure and well-maintained engines. Measure real mpg and idle hours first so you can see what changed.
See FleetZap on your own fleet
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