I'll push this back to the top of the page as top cylinder lubrication injection systems are often the first mod that LPG conversion vehicles are given in some countries. Could top cylinder lubrication give some improved FE in gasoline engines.
I nominate you to aquire a baseline MPG in the gaslog (4 entries ) then purchase the top engine lubricator, and test it on your vehicle.
And I supose its possible for such lubricants to increase efficiency in gasoline engines.
"You have to know the truth, and seek the truth, and the truth will set you free."
I've used some 100:1 synthetic 2 stroke oil mixed with my gasoline, and lucus top end lube, and didn't notice a big change, I have done this both in my cars gas, and my 125cc motorcycle, neither one showed much of a change, I am willing to try again in both vehicles in the spring as right now it's cold out side and my mpg are really poor.