Just read a thread over at fordf150.net on some of them adding acetone to their gas. About 2.5 ounces per ten gallons. A lot have claimed increased, 15 to 35%, mpg. Some have mentioned acetone "eating" the non-metallic parts up in the intake system.
Dupont Dow Elastomers sent me a nice 40-page report on Viton (fuel system rubber) in various fuels.
The exact one we are interested in, namely 3% acetone in unleaded gas, was not in there, but we can extrapolate it.
ASTM Fuel C is isooctane gas and toluene blend, and used to simulate high-octane gas in tests like this because it behaves about the same, and is standardized and you do not need to worry about additives screwing up the test results.
MBTE is the famous octane booster supposedly found in mother's milk in the NE US.
Code:
Fuel Swell % 7 days at 20C ASTM Fuel C
Conc MTBE Acetone
100% 122 181
75% 84
50% 37
25% 22
0 6 6
3% 9.5 16
Fuel swell is a measurement of how the fluid is eating up the rubber.
Acetone is about 50% higher than MBTE in this test. Zero acetone and zero MBTE gives about 6% swell under these conditions. This is about the same as premium unleaded gas.
If you do linear extrapolation on this (R-squared=.92), 3% MBTE should give you about 9.5% swell, and acetone should give you about 16%. You get about the same result if you estimate 3% acetone by multiplying the MBTE estimate by 181/122.
Here are some other swell figures from the literature (similar conditions)
Code:
90/10 Fuel C/Ethanol 13%
85/15 Fuel C/Methanol 20%
Shell SU-2000 Unlead 10%
Regular unleaded 2-4%
So the bottom line on this: Based on the literature, we would expect the acetone to cause a slightly elevated rate of degradation of the rubber in the fuel system, unless specifically formulated for it. This rate of degradation is higher than normal gas, but on par with such stuff as ethanol or methanol.So, search your soul on whether you want to do this or not, but chances are if you have a beater, the increased rate of rubber decay will not be fast enough to affect you compared to other issues, such as the car falling apart, etc. But I would say if you have a new car, maybe better lay low on this to avoid having to replace some of the rubber components at some time during your car life.
There is one possible exception, which is the fuel filler hose, the hose that runs between your gas cap and the tank. If you pour straight acetone down this, I am thinking this will be bad, because it is not diluted. If this hose gets cracked and gets holes in it, this will be a source of hydrocarbon emissions (vapors from your gas tank will get out, not to mention possibly some gas), and also, the PFD (pressurized fuel delivery) sensor will cause the "check engine" light to come on in your car annoyingly. So, if you do this, pre-mix the acetone with a little gas before adding it to the gas tank to save the life of this hose. Make sure to include this gas in your MPG calculations.
Sorry to bore the casual non-nerd forum viewers, but there is a point to all of this, which I will make in the next post.
Soooooooooooooo, what do ya'll think? Snake oil, myth or true?
Dupont Dow Elastomers sent me a nice 40-page report on Viton (fuel system rubber) in various fuels.
The exact one we are interested in, namely 3% acetone in unleaded gas, was not in there, but we can extrapolate it.
ASTM Fuel C is isooctane gas and toluene blend, and used to simulate high-octane gas in tests like this because it behaves about the same, and is standardized and you do not need to worry about additives screwing up the test results.
MBTE is the famous octane booster supposedly found in mother's milk in the NE US.
Code:
Fuel Swell % 7 days at 20C ASTM Fuel C
Conc MTBE Acetone
100% 122 181
75% 84
50% 37
25% 22
0 6 6
3% 9.5 16
Fuel swell is a measurement of how the fluid is eating up the rubber.
Acetone is about 50% higher than MBTE in this test. Zero acetone and zero MBTE gives about 6% swell under these conditions. This is about the same as premium unleaded gas.
If you do linear extrapolation on this (R-squared=.92), 3% MBTE should give you about 9.5% swell, and acetone should give you about 16%. You get about the same result if you estimate 3% acetone by multiplying the MBTE estimate by 181/122.
Here are some other swell figures from the literature (similar conditions)
Code:
90/10 Fuel C/Ethanol 13%
85/15 Fuel C/Methanol 20%
Shell SU-2000 Unlead 10%
Regular unleaded 2-4%
So the bottom line on this: Based on the literature, we would expect the acetone to cause a slightly elevated rate of degradation of the rubber in the fuel system, unless specifically formulated for it. This rate of degradation is higher than normal gas, but on par with such stuff as ethanol or methanol.So, search your soul on whether you want to do this or not, but chances are if you have a beater, the increased rate of rubber decay will not be fast enough to affect you compared to other issues, such as the car falling apart, etc. But I would say if you have a new car, maybe better lay low on this to avoid having to replace some of the rubber components at some time during your car life.
There is one possible exception, which is the fuel filler hose, the hose that runs between your gas cap and the tank. If you pour straight acetone down this, I am thinking this will be bad, because it is not diluted. If this hose gets cracked and gets holes in it, this will be a source of hydrocarbon emissions (vapors from your gas tank will get out, not to mention possibly some gas), and also, the PFD (pressurized fuel delivery) sensor will cause the "check engine" light to come on in your car annoyingly. So, if you do this, pre-mix the acetone with a little gas before adding it to the gas tank to save the life of this hose. Make sure to include this gas in your MPG calculations.
Sorry to bore the casual non-nerd forum viewers, but there is a point to all of this, which I will make in the next post.
Soooooooooooooo, what do ya'll think? Snake oil, myth or true?
