Yes, unleaded street fuel. In the '70's the plug on the right in your previous post was the normal for leaded street fuels. What is the composition of 110 race fuel?
I could post many many more pics of tanned plugs on modern street fuel.........with no greyish tinge. Its no different to the people who claim modern fuels show white plugs.....
The composition of race fuel is the same as street fuels......They are both hydrocarbons it just depends on what the fuel chemist decides best suits the application. They also make about the same power.
