Yes, it works the same way as long as there's no load on the engine. As soon as the engine goes from light-throttle cruise to pulling or accelerating, the vacuum advance drops out of the picture and the spark is retarded somewhat, because of a drop in manifold and/or venturi vacuum. That prevents detonation from over-advanced ignition timing when the engine is in a loaded situation. It's usually a difference of 5 to 8 crankshaft degrees, sometimes as much as 10 degrees on some distributors. For instance, a small block V-8 develops its best power under load at about 36-37 crankshaft degrees, and the best fuel economy at light throttle cruise happens at around 42 to 46 degrees of advance.
Jerry
