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Discussion Starter · #1 ·
So far after two months, I am seeing a 20-25% increase in MPG in my '91 Honda CRX Si. Normally, in typical work/weekend driving, my fuel gauge needle is at the half-tank mark after driving 100 miles. After adding 2 oz. of Acetone to the 12.9 gallon tank just before a fill-up (the first time- see below), I now see 120-125 miles driven at the same needle position. There is no change in driveability and I had no problems a few weeks ago when the car sat out in 16 degree weather overnight.

BTW, I pay about $5 for a pint of acetone at WalMart. I generally fill-up when needing about 7.5 gallons, so to get a 2 oz/10 gal mixture, I add 1.5 ounces each time now, raising my cost per gallon by about 6 cents (47 cents/fill-up). So, if gas is $2.35/gallon, my per gallon cost goes up by just over 2.5%- not bad to get 20-25% better gas mileage!

How to get more gas mileage by adding Acetone (CH3COCH3) to your gas tank.

Remember the old "I've got good news and bad news" way of telling a story, well, let's start with the good news. Acetone is a chemical found in paint thinner and when added to gasoline can boost your gas mileage through the roof. You don't have to add much and the results are amazing. The catch is a risk of flamability if you store it improperly, and if you car has cheap plastic innards, the acetone will eat through everything. However, the short article is excerpts from a looonnnggggg piece that covers everything, including a guy who soaked engine parts in pure acetone for months and found that it was safe despite the warnings. Interesting…


Graph D is for Diesel. A-C are different brands of Gasoline.

Note that using more than 3 oz. per 10 gallons of gasoline starts reducing the MPG gain, and anything much past 5 will result in worse than stock MPG. Amazing that the miniscule percentage that I'm adding is producing such a fantastic result. The ratio of acetone to gasoline is approximately 1/641.

Short article http://www.realtechnews.com/posts/2598

Full article http://www.pureenergysystems.com/news/2 ... 9_Acetone/

Note, this information is for educational purposes only. If you f*ck-up your car, I'm not responsible. (per my brudder, the Lawyer)
 

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Yeah... If you look at the formula 'squared posted, it's nothing but carbon, oxygen and hydrogen - stuff that's already present when burning gasoline. Burning it probably won't release as much energy, but that doesn't mean the resulting compounds will be any different.
According to wikipedia, converters can be clogged by sulfur, zinc and phosphorus among other things.
Under O2 sensors, it lists lead (from fuel additives), phosphorus (from oil additives) and silicon (from sealant and coolant).
 

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crxsquared said:
Normally, in typical work/weekend driving, my fuel gauge needle is at the half-tank mark after driving 100 miles.
Really? Obviously that's not an accurate measure of a half-tank, but it's still crazy. In any case, though, I would hope that you are judging your gains by something a little more "standardized" than simply eyeballing the half-tank mark of an obviously inaccurate gas gauge. Most people use the auto-shutoff of a gas pump to tell them the amount of gas that's been burned since the last auto-shutoff fillup, and use the trip odometer to calculate mileage thusly. Not perfectly accurate, but better than anything using a gauge that says it's taken you more than 6 gallons of gas to travel 100 miles...in a CRX. Even with perfect measuring devices, though, I question results like these. If you want the gas additive to work, you can very easily (and even subconsciously) alter your driving patterns enough to cause a noticible difference. The best way would be a blind study where someone else fills your tank and then either adds a shot of acetone or simply a shot of gasoline (without telling you which), drive tankful after tankful (lots of different driving conditions can make a big difference, but given enough time they would tend to average themselves out) and THEN compare your mileage results to the acetone/non acetone information. Sound like a pain in the ass? Sure. But it would be a lot more believable. Otherwise, there might not be much more to it than a "placebo effect".
 

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Acetone in fuel is not a new idea. It's been around for a long time. A couple of years ago there was a post about it in my motorcycle group, and someone posted a link discrediting it. I'm not saying I necessarily agree or disagree though.
Using the gauge as a measurement the way he said it is fine, you know about how much you can go at X place on the gauge. Obviously, the more accurate way would be to average your mileage over a few tanks and see what you get. Honestly though, a CRX in good condition should get great mileage. I have had as high as 44mpg (using the pump/odometer method) driving home in the snow, and as low as 18 mpg (2 autocrosses in one weekend, with a lot of spirited driving) with my A6. I find that highway driving is not the best mileage, since the Si tranny is so low-geared, cruising at 75-80 mph-- oops I mean at the posted limit of 65 mph-- makes the engine rev a little high. 55 mph country highways are the best, and driving in the snow, a gear higher than I normally would be, is the best.
 

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I tried the acetone. No difference. I suspect some see a gain because it might clean up their burn and make up for a bad tune.

With everything set right and properly maintained, I get 32 mpg with my DOHC ZC. I have tried driving like a granny but could not keep it up. I like to accellerate and am usually the second fastest car on the highway. Driving like that limits one's mileage. :D
 

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I heard about it some time ago and haven't had the courage to try it out. One of my worries is this: sure enough the metal parts will not be damaged by acetone but we do have a "varnish" coating in our fuel tanks, and also a few seals along the way, including the injector seals - are they not likley to get damaged eventually?

JP
 

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I doubt such a small amount (1.5 to 3 oz per 10 gal) would do anything. But again, why risk it when I have seen no empirical evidence of savings on a healthy car. You really would need to duplicate conditions exactly in order for the results to have any validity.
 

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I am leary of trying this in my CRX only as I have not been convinced that it will be safe to the car's internals. I would hate to have to pay more to fix the car than the gas savings would have ever been.

If it is fine, then it woul'd be great, especially once I've got my swap done and need premium gas which is presently, an unusually high $1.17/litre.
 

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OBD1 Kenobi said:
If it is fine, then it woul'd be great, especially once I've got my swap done and need premium gas which is presently, an unusually high $1.17/litre.
Over here we are looking at US $1.35/litre! And the per capita annual income is about US $5000...

I may give the acetone a try - the car is not new anymore and I have test equipment which can test for increased or reduced emissions. Now I just need to get a new battery for that car first ...

JP
 

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Second tank - 2 oz per 10 gallons gave me 35 MPG. Mix of highway and around town... about 2/3 highway. Again, what I would expect.

Third tank - 2 oz per 10 gallons gave me 39 MPG. All highway driving, averaging 75 MPH... No different than the first tank.
 

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My tankfull before: 27mpg, no acetone
last tank full: I think 2 oz, 25mpg (I need to check my container size)

All pizza delivery/city driving.
I think I still have the timing a little retarded from the trip, the highest octane in some of the places I went was 90 for super, so I backed it down a little.
(y8 mini-me)
 

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Discussion Starter · #19 ·
Don't know why others aren't seeing a MPG increase who've tried acetone, but I just filled-up this morning, and I am still getting about a 20% improvement in fuel economy for my '91 Si, 8 weeks after I started adding the stuff. Put in 7.075 gallons after running 238 miles, for 33.6mpg in mixed highway/city driving. My commute is about 10 miles each way, with half of it being stop and go city driving with about 8 traffic lights thrown in (stopped by at least 2/3 of the #$%^ things!), with the other half a blast down I-95 at 70-75mph (just to keep up w/ traffic).

Oh, and I had the price of acetone wrong- it's $5 for a QUART, not a pint of the stuff. Gas was $2.499 this morning. 1.5 ounces of acetone cost me about $.25, so for a 1.4% increase in fuel cost, my mpg went up 20% from my pre-acetone baseline of 28mpg.

Works for me. And as for the acetone affecting the car's fuel system, 11.9 gallons (full tank) is 1523.2 ounces of fluid. If you have 2 ounces of acetone in that, it's only a 0.13% solution (ratio of gas to acetone, 760/1).

Hmm, just thought of something. I reset my ECU after putting in the first two ounces, just so the computer would have to recalibrate the fuel/air/timing. Did anyone else think to do that?
 

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Quote, originally posted by Car Talk »
Click and Clack Talk Cars
By TOM AND RAY MAGLIOZZI - 01/21/06

Dear Tom and Ray: Last week my neighbor gave me an 11-page treatise on the benefits of putting a small amount of acetone in your gas tank: an increase of 25 percent to 35 percent in gas mileage with NO damage to the engine.

The article tells how much acetone per number of gallons and gives the rationale for why it works. I am NOT knowledgeable in the workings of engines, nor do I have knowledge about fuels, so I can be snowed by people who may or may not know what they are talking about. I value your opinions. What do YOU think about this? - Wil

TOM: It's bo-o-o-o-gus, Wil. With four "o's." Don't put acetone in your gas tank.

RAY: It does absolutely nothing to increase your gas mileage. We spoke to a fuel-systems engineer who works for one of the major oil companies. He said that because of all these rumors floating around on the Web, his company tested acetone in its own labs and found no increase in mileage. None. And he said the equipment is precise enough to detect anything over a 1 percent difference.

TOM: But it's worse than useless - it's also harmful. Acetone is the primary ingredient in nail-polish remover. And while it will burn and is a high-octane material, it's also a very powerful solvent. So while it's in your fuel system, it'll be eagerly dissolving all of your rubber components ... like gaskets and O-rings.

RAY: In fact, some cars have a rubber hose in the fuel line that goes between the fuel-cap assembly and the tank. When you add your acetone, pouring 100 percent, undiluted rubber-eater right onto that tube, you'll be eating through it in no time.
*

TOM: Here's our final reason not to use it: It dissolves paint. So if you slip and spill a little bit outside your fuel filler door, you'll have a nice, unpainted line running down to the bottom edge of your rear quarter panel. When we see you drive by, we'll know you didn't take our advice!

http://www.fuelsaving.info/acetone.htm
http://honda-tech.com/zerothread?id=1583353&page=1

Just chiming in ;)
 
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