Is converting your fleet to CNG worth the investment? Enter your fleet details below to see annual savings, payback timeline, and environmental impact.
Gasoline Gallon Equivalent
Federal/state incentives
CNG conversion pays for itself
$226,496/yr
annual fleet savings — payback in 21 months
Annual Fleet Savings
$226,496
Savings per Vehicle
$11,325
per year
Total Investment
$400,000
$20,000 net/vehicle
Payback Period
21 mo
1.8 years
5-Year Net Savings
$732,479
After investment recovery
CO2 Reduction
465 tons/yr
27% lower lifecycle emissions
| Metric | Diesel | CNG | Difference |
|---|---|---|---|
| Annual Fuel Volume | 153,846 gal | 170,940 GGE | - |
| Fuel Price | $4.25/gal | $2.50/GGE | -$1.75 |
| Annual Fuel Cost | $653,846 | $427,350 | -$226,496 |
| Investment (net of credits) | - | $400,000 | one-time |
| Year | Fuel Savings | Cumulative | Net (after investment) |
|---|---|---|---|
| Year 1 | $226,496 | $226,496 | $-173,504 |
| Year 2 | $226,496 | $452,992 | +$52,992 |
| Year 3 | $226,496 | $679,488 | +$279,488 |
| Year 4 | $226,496 | $905,984 | +$505,984 |
| Year 5 | $226,496 | $1,132,480 | +$732,480 |
Ready to convert your fleet?
Get quotes from certified CNG conversion installers.
No obligation. Free. Takes 30 seconds.
This tool compares the total fuel costs of running your fleet on diesel versus compressed natural gas (CNG). It accounts for the slight fuel-economy penalty of CNG engines (~10% lower MPG) and factors in conversion costs, available tax credits, and the resulting payback period.
Annual diesel cost is calculated as vehicles × annual miles ÷ diesel MPG × diesel price per gallon. CNG cost uses the same formula but with a 0.9 efficiency factor on MPG to account for the lower energy density of CNG. The difference between these two costs is your annual fuel savings.
CO2 reduction is estimated at approximately 27% lower emissions for CNG compared to diesel on a per-mile basis, based on EPA lifecycle analysis data.
| Fleet Size | Typical Annual Savings | Payback Period |
|---|---|---|
| 10-25 vehicles | $30,000 - $100,000 | 24-42 months |
| 25-50 vehicles | $100,000 - $250,000 | 18-36 months |
| 50-100 vehicles | $250,000 - $600,000 | 15-30 months |
| 100+ vehicles | $600,000+ | 12-24 months |
CNG infrastructure costs (fueling station) are not included in this calculator but can add $500,000-$2,000,000 for on-site fueling. Public CNG stations may be available in your area. Federal tax credits of up to $64,000 per vehicle may apply under the Alternative Fuel Vehicle Refueling Property Credit (IRC 30C).