The economic return to a fleet owner for switching to Dual-Fuel, Diesel / Natural gas, requires a number of inputs to evaluate.The most important variable is the price of diesel and the price of gas compared on the basis of its calorific value. There is world wide move to retail gas using units of gas quantity in the same units as the liquid fuel, hence “Liters Equivalent”. This reduces and standardises the data required for the calculations.

In D/F mode the thermal efficiency of the engine, other than at full torque is less than that of diesel. The Dual Fuel Product maximises the fuel efficiency at every engine operating point so this is never a problem, as long as the cost of gas is less than about 90% of the cost of diesel. You will still make money.

The DieselGas process for developing the data set requires that the engine be installed in our test cell under fully controlled conditions where the engine can be mapped at many different operating points in the original diesel configuration. Typically about 1000 points is used on a grid of RPM’s Load and environmental temperature.Each point is then run using gas and the combustion optimised primarily for highest engine efficiency. This is often also the point of the least harmful emissions and CO2 production.

The data is then translated and down loaded into the Dual Fuel Controller (DFC) to enable it to reproduce the performance on the road. The DFC records in a statistics file, the operating point of the engine every second into 1 of 300 bins. From this data and the actual cost of fuel, the accuracy of this web calculator can be verified.

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