oh the infamous acetone!! and chase of illusive mileage...
this is, by far, not the first acetone discussion i'll participate in. prolly, not the last one.
1. most of those discussions are done by folks that have NEVER EVER tried acetone, for any reason, but have their "opinion".
2. most have NEVER EVER read the original research on this done by Louis LaPonte.
with this being said, let me say something:
i used acetone in several vehicles, for about a year. i tried it on several vehicles, with no success. i am a meticulous person in this respect, so i had a daily mileage log for about year and a half.
with this being said, here's the results:
1. 2004 Honda CR-V - solid 10% mpg improvement with approx 3 ounces to ten gallons.
2. 99 Ford Ranger - i could get that little truck to 32 mpg with 3oz/10 gall
3. 99 Lexus RX300 - no result
4. 2000 Chevy Silverado - no result.
5. vehicles 1 and 2 were treated with acetone for over a year, w-out any adverse results. LaPonte been experimenting with acetone since mid 50s, i believe, had seals and gaskets stowed on cans filled with acetone for extended period of time, w-out them being damaged. PURE ACETONE, not minuscule 3oz to 10 gall solution.
those with "opinion" should go to any parts store and read chemical configuration for most of OTC cleaners/gas treatments sold there. it is common for them to have more acetone in them, than one will have in 3/10g solution. this should take care of "it will damage this and that" opinion.
here's probably the best source of info on the question:
btw, why any mpg improving additive is not used by fuel makers (au contraire, here in the USA, fuel is produced to reduce mpg, not to improve it; before bashing me, look at European cars mpg and ask if they have gasohol or "winter formulation" sold there): because it is all owned by the same cartel that makes $$ off every end. less efficient vehicles + less efficient fuel= more profit.
BEWARE: NO ONE ADDS METHANOL TO FUEL; it WILL damage engine because it flushes oil off moving parts; weak methanol/water mixture, alias windshield washer fluid, is used as injected spray in turbochargers, on race cars, to cool down exhaust; even that poses major issue for turbos.
PS. please, do not start argument on this. it is not worth it. it is absolutely personal decision to try it or not. it is what it is, it works on some engines, it does not work on others; it can probably damage some cheap material parts or parts sensitive to it, like Prius tank lining. water can kill if taken in excessive amounts, and any medication is controlled toxin. take it easy.