Bi-fuel – A fuel with many advantages

There is great po­ten­tial for Com­pres­sed Natural Gas (CNG) due to it hav­ing very low emis­sions. Com­pared to gaso­line, CNG com­bus­tion pro­duces about 25% less car­bon di­ox­ide (CO₂). Fur­ther­more, CNG has a great po­ten­tial for re­duc­ing un­treated emis­sions. The ex­haust gas is odor­less and con­tains no par­ti­cles.

CNG also has an ad­van­tage when be­ing pre­pared as a fuel:
it needs no ad­di­tives and its pro­duc­tion does without com­pli-
­cated re­fin­ing pro­cesses. Another ad­van­tage is that CNG ve- hicles place no load on the world's scanty pe­tro­leum re­sour- ces. Methane, CNG's ma­jor compo­nent, can also be pro­duced from or­ganic sub­stances. This closes the CO₂ cy­cle and long-term avail­ability is in­creased even fur­ther.

CNG vehicles have proven them­selves for years now. Since
CNG fill­ing sta­tions are still few and far be­tween, the vehicles
are mostly equipped with bi-fuel sys­tems, and the en­gine can
run on ei­ther natural gas or gas­oline.

CNG has a very high knock resis­tance (130 ROZ as op­posed
to be­tween 91 and 100 ROZ for gas­oline). This re­presents fur-­ther potential for op­timiza­tion of the CNG en­gine. This is ide­ally suited for super­charging, al­low­ing down­sizing concepts to be ap­plied with the ac­compa­ny­ing im­prove­ments in effi­ciency.