[SAJ]

Three things. 1) 29.58 ml/fl.oz. So, 6 ml for 1 gallon is about right (it's a bit low, actually; 7 ml is somewhat more precise), 2) make certain you're using a 1% solution of acetone, 3) uh, acetone is a solvent; it dissolves many plastics, and certain other materials, quite readily.

In filling up a 15-gallon tank, use 3.54 oz (3.5 is certainly close enough) of 1% acetone. This is approximately 7 tablespoons (use a metal tablespoon, ok?).

On your second full tank and thereafter, you should see something on the order of 3 mpg better fuel mileage.

If you're near a chemical plant, you might inquire about getting some waste trimethylbenzene or even xylene from them. Small amounts of these can bump your mpg another 2-3.

[SAJ]

Sorry, typo. For ‘’1%’’ please read ‘’100%’’. Purity is VERY important, btw, or your engine will run rough.

[tacticalogic]

it dissolves many plastics, and certain other materials, quite readily.

It also dissolves "varnish" deposits in fuel injectors, and on intake valve stems. Valve lifters will accumulate a ring of varnish around the bottom that makes them not want to come out of the hole if you have to replace them. We used to dribble acetone or lacquer thinner down a length of welding rod held at the edge of the lifter and let it run down between the lifter and block to soften it up so they would come out easier.