1/30/2006

Better mileage with acetone? I doubt it.
Filed under: Acetone & Gasoline,Energy,Engineering,General,Technology — nobrainer @ 1:43 pm

UPDATE (7/3/2006): Engineers at Kettering University have yet to replicate the claims of Louis Lapointe.
UPDATE (1/3/2007): Mythbusters was unable to validate claims that acetone will increase your fuel mileage.
UPDATE (1/21/2007): Acetone probably can’t improve the surface tension of gasoline.
UPDATE (1/21/2007): Oil companies make most acetone.

Note: This was the first in what became a series of posts about the purported benefits of adding acetone to gasoline. As such this is perhaps the least useful of all the posts I wrote. The most salient points are that only an extreme few are able able to get a 25+% increase in mileage and no one with any widespread credibility has been able to get significant improvements under laboratory conditions.

The original post continues below:

In a few instances, I have seen fark reference some work suggesting that adding small amounts of acetone to your fuel will increase your fuel mileage by up to 30%.

Today’s link goes to RealTechNews. That’s just the same information posted at PureEnergySystems. That information was written by a guy named Louis LaPointe. Both show the same graph, which is pretty non-descript. It’s the kind of graph that would earn you an F in most high school classes, let alone a college class with a professor like Leo Gaddis.

Fuel mileage curve with acetone

The links all use this same graph. It shows no data points. It does not tell us what kind of cars were used, although in one article it is explained that curve D is for a diesel engine. All the graph really tells me is that someone drew some pretty lines.

There really isn’t much methodology to be digested. Most of the information isn’t even brought close to your plate. The best you can get is that someone is adding acetone to their vehicles and basing the information off of runs done somewhere at 50 mph.

More links:
DIY Live
PureEnergySystems Wiki
FuelSaving.info

The DIY link is the same as the first 2 links but with less. The PES Wiki link involves numerous user testimonials, some good, some bad. It also took me to a link about calculating fuel mileage savings, which used an erroneous formula. (A hint: getting a 100% increase in mileage won’t reduce your fuel costs by 100%.)

There is some good information about being consistent while you test. But still, I don’t really trust individuals looking for results to give very good data. The article at fuelsaving.info is a counter to the pro-acetone group. I’m inclined to side with that article.

Here’s something that caught my eye:

Many products claiming to improve mileage are expensive and do not really help much. Others are fakes. For instance, a SMOOTH flow of air into a carburetor or injector is far better for mileage than turbulent air. Turbulence is bad. Yet many people deliberately introduce turbulent air into their engines. There are many silly myths floating around the car industry to fool the average person. Another is that cold intake air improves mileage. NO. Warm air improves mileage.

If I’m not mistaken, fluid flows much better under turbulence. Everyone from ship to airplane builders and golf ball designers know this. Per Parviz Moin and John Kim in the SEAS at UCLA:

In the cylinders of an internal-combustion engine, for example, turbulence enhances the mixing of fuel and oxidizer and produces cleaner, more efficient combustion.

Also, cold intake air, I believe should increase motor efficiency. The idea is that cold air is more dense. Thus each volume of intake air has a greater mass of oxygen. Oxygen, of course, is completely necessary for combustion of organic materials like gasoline. However, cold air will, due to its density, increase the air drag on a vehicle. So in real world conditions, there is a trade-off to be made.

So why should we trust Louis LaPointe?

FACTS. Absolute true facts. My Scan Gauge does not lie and neither do I. What data do these people show? Actual data. Actual test results.

Well his facts and test results aren’t that good. For example:

My 1995 Neon that is now 10 years old at 130,000 miles and runs with acetone all the time. It runs perfectly. Absolutely perfect. Just averaged 45 MPG IN TOWN last week. And just last weekend we averaged 50 to 73 MPG on a test run through Wisconsin with special mileage devices attached. Never had engine work.

50 to 73 MPG? That’s a huge variation. Is that for a whole trip? Is the 73 MPG just from that 1 mile where you tailgated an 18-wheeler? His FACTS, are pretty much anecdotal in my opinion.

Personally, I believe the guy is just try to sell the ScanGuage (Evan & Bear, you ought to offer to revamp their website). Damn near every link names this singular device and suggests that you should buy it to test your car.

Does acetone really work? I don’t have the guts to find out for myself. The risks of voiding a warranty, corroding my fuel system, or even spilling the acetone on my paint and ruining it are just too much for me to take.

If you are interested in improving your mileage, your best bet is still to be a good driver with a well maintained vehicle. Keep your tires inflated properly. Don’t run the AC. Keep your engine tuned. Don’t carry around unnecessary weight. Perhaps most importantly, accelerate and brake as slowly as possible. Gunning your engine and braking hard will probably do more to hurt your mileage than anything else. The key is to be gentle with the pedals. And remember, in this house, we obey the laws of thermodynamics!


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