LPG consumption and cost per distance
LPG can require a different fuel volume, so equal consumption with petrol is not assumed. Enter your measured increase, fuel prices and extra maintenance cost. Deduct annual additional maintenance from fuel savings; the remaining amount determines payback.
payback months = conversion cost ÷ net monthly savings
Savings example
At 8 L/100 km petrol priced at $1.50/L and a 20% LPG consumption increase, LPG use is 9.6 L/100 km. At $0.80/L, fuel costs $7.68 instead of $12 per 100 km. Across 12,000 km annually, fuel savings are $518.40 before maintenance, or $418.40 after $100 extra annual maintenance.
When there is no payback
If net savings are zero or negative, no payback period is shown. Include petrol used for starting and warm-up in your measured costs; this tool has no separate startup model. Taxes, insurance, conversion requirements and future fuel prices are not inferred.