Enter Your Dual Fuel Data
Cost Comparison Graph
The chart compares monthly, annual, and total period cost. It also plots cumulative savings for the alternative fuel across the selected months.
Example Data Table
This example shows how a typical petrol versus CNG comparison may look.
| Scenario | Monthly Distance | Fuel A | Fuel B | Fuel A Cost/km | Fuel B Cost/km | Estimated Monthly Savings |
|---|---|---|---|---|---|---|
| Urban commuter | 1,600 | Petrol at 1.30 per Liter, 13 km/Liter | CNG at 0.80 per Kg, 20 km/Kg | 0.10 | 0.04 | 96.00 |
| Long-distance driver | 2,800 | Diesel at 1.22 per Liter, 17 km/Liter | LPG at 0.95 per Liter, 12 km/Liter | 0.07 | 0.08 | -28.00 |
| Balanced mixed use | 2,000 | Petrol at 1.35 per Liter, 14 km/Liter | CNG at 0.85 per Kg, 21 km/Kg | 0.10 | 0.04 | 116.00 |
Formula Used
Cost per km = Fuel price per unit ÷ Efficiency
Monthly fuel cost = Monthly distance × Cost per km
Monthly total = Monthly fuel cost + Monthly maintenance adjustment
Total analysis cost = Monthly total × Analysis months + Setup cost − Recovery credit
Savings = Base fuel total cost − Alternative fuel total cost
Break-even months = Net upfront cost ÷ Monthly savings
Net upfront cost equals alternative fuel setup cost minus the expected recovery credit at the end of the selected period.
How to Use This Calculator
- Enter your currency symbol and preferred distance unit.
- Add the distance you usually drive each month.
- Set the number of years for your ownership comparison.
- Enter any conversion kit cost for the alternative fuel.
- Add any resale or recovery credit you expect later.
- Enter both fuel prices, unit labels, and efficiency values.
- Add monthly maintenance differences for each option.
- Press Compare Fuel Costs to view results, payback, chart, and export options.
Frequently Asked Questions
1) What does this calculator compare?
It compares two fuel options for the same vehicle using price, efficiency, monthly distance, maintenance adjustments, conversion cost, and recovery credit. It then estimates monthly cost, annual cost, total ownership-period cost, and break-even timing.
2) Can I compare petrol vs CNG or diesel vs LPG?
Yes. You can rename the fuel fields to any two options you want. Enter the correct price per unit, efficiency, and monthly maintenance amount for each fuel to get a like-for-like comparison.
3) What should I enter for efficiency?
Enter the distance your vehicle travels per one unit of fuel. For example, use kilometers per liter, miles per gallon, or kilometers per kilogram. Keep both fuels in the same distance unit for valid results.
4) Why include maintenance adjustments?
Some fuel systems may change service frequency, filter replacement cost, injector wear, or tune-up cost. Monthly maintenance adjustments let you reflect those differences instead of comparing fuel price alone.
5) What is the break-even result telling me?
Break-even tells you how long it may take for the alternative fuel savings to recover the upfront setup cost, after considering the recovery credit. If savings are negative, no break-even is reached.
6) Why can the cheaper fuel still lose overall?
A fuel can be cheaper per unit but still cost more overall if the vehicle is less efficient on that fuel, maintenance is higher, the conversion cost is large, or the analysis period is too short.
7) Should I use monthly or annual distance?
This calculator uses monthly distance because it makes payback timing easier to understand. Annual figures are calculated automatically by multiplying your monthly result by twelve.
8) Are taxes, insurance, and resale fully covered here?
Only fuel cost, maintenance adjustments, conversion setup, and recovery credit are included directly. Insurance, taxes, financing, and repair risk should be reviewed separately if you want a broader ownership-cost decision.