Duel- Fuel system installed CNG and diesel 70% 30% split

[cRiPpLe_rOoStEr]

Even a smaller ratio of CNG eventually being supplied through port-injection would already be likely to make sense. Considering that most of the urea currently used for DEF production relies on natural gas as a feedstock, in the end it might also be more efficient to use the gas directly.

[cRiPpLe_rOoStEr]

It's been a while, but in the meantime dual-fuel Diesel-CNG setups are becoming more common in some regions of my country, most noticeably in the Southeast between Rio de Janeiro and São Paulo.

[Charlie Cheap]

Years ago I converted our city fleet to duel-fuel gasoline/propane. Using CNG drops the HP considerably and in police patrol cars it was too much of a power loss. Also, this was in the 1990's and in Texas LPG was cheap. LPG losses was about 10% of gasoline and in a chase they simply let off the throttle, switched back to gasoline, and continued the pursuit. At a show for duel-fuels a truck company owner showed my Public Works Director and me his LPG-Diesel setup. He gained considerable MPG and a gigantic HP gain...to the point he had to fire a couple of drivers for burning out clutches racing other trucks in Colorado. He said, they would start up a mountain behind a normal diesel rig, then blow by them at some crazy speed...which eventually fried the clutch. After a few very expensive clutch replacements, the drivers had to be fired. When gasoline was $3.50 to $4.00 a gallon LPG was .75 cents, and it ran much cleaner. I went back a few years after retiring and the LPG station I built was no longer in use. The mechanic said the new Fords ran as clean on gasoline as LPG when I ran the shop. I guess we are making improvements.

[cRiPpLe_rOoStEr]

Originally Posted by Charlie Cheap

Years ago I converted our city fleet to duel-fuel gasoline/propane.

Besides forklifts, tractors and some other special equipments, LPG is not legal as a motor fuel in my country.

Using CNG drops the HP considerably

It used to be worse, but nowadays the power loss is only noticeable if the mixture is set too lean. Since CNG is less prone to knocks as gasoline and ethanol, it's not so unusual to set the mixture excessively lean as an attempt to increase the savings, even though it's objectionable not only as there is a greater tendency to overheat but also due to the need to rev higher under some circumstances.

At a show for duel-fuels a truck company owner showed my Public Works Director and me his LPG-Diesel setup. He gained considerable MPG and a gigantic HP gain

Either LPG or CNG provide some gains on Diesel engines as they increase the flame spread leading to a more complete combustion, and decrease the NOx emissions as they take displace an amount of both Nitrogen and Oxygen at the intake charge, yet not enough to prevent the combustion of both Diesel and the gaseous fuels in use.