Does Acetone Addition to Fuel Lower Consumption?

[Wonko the Sane]

Hey, Wonko. I think I agree that the Acetone might be leaving the fuel over time. And, I suppose that the rate of evaporation accelerates with increases of fuet tank temperature and with agitation. But, would you explain how you are determining the relative rate of fuel consumption in the first portion of your tank full vs. the later portion? Are you simply judging by the fuel guage and odometer? Dave.

Hey, Dave:

Also, as the fuel is consumed, the increasing ratio of air to liquid means that the acetone wants to leave the diesel. Maybe if the fuel tank was a bladder that collapsed so that there was no headspace the acetone would hang around longer.

Yeah, I estimated the amount of fuel consumed using the fuel gauge.

I've been doing the same weekly routine (about 300 miles, 50%Hwy/50%City) for the last four years. My car has been getting 40 mpg like clockwork, never more than 41 and never less than 39. So I notice that after filling up, the fuel needle never moves off "F" until 90 miles (2 and 1/4 gallons). It reaches 7/8ths at 150 (1.5 gallons), 210 miles at 3/4, 270 at 5/8th, etc.

On my first tank, the needle moved at about 110 miles (20/2.3 gal = 8-9 mpg improvement). The needle reached 7/8ths at 175 (5/1.5 = 3 mpg improvement). The next three gallons showed maybe 5 miles improvement. And no improvement was seen after that.

My second tank was not as good improvement, but showed the same trend.

I can understand the skeptics wanting more accurate quantitation.

That's why I wonder if the TDI Club members that can monitor MPG as a function of time and mileage can participate using an "acetoned" tank.
Isn't there a dashboard display upgrade with a trip computer that tells instantaneous MPG?

 

[JetPuf]

Vag-com can be used to compute instant MPG

 

[djmeier1]

Wonko, I respect your observations as to fuel burn. But, I just want to classify them as to weight. What I have been doing is not much better, although I do think that keeping records as to miles attained per gallon of fuel added to the tank would be helpful.

And, I do agree that this group has enough members focused on fuel economy to perform a very credible reaearch project with regard to acetone additive. I don't know that sufficient of them could be enlisted in the project, but it would be a pretty good way to address the issue, if we could.

Changing subjects, I agree that we have two distinct issues to track now, as the engine operating temperature appears to be pretty important and pretty variable. The range of thermostats listed by Dangerous_Dan piques my interest. I don't know what temperature is recommended for my Jetta nor whether the installed thermostat is the one specified. I'm interested in learning more (Dan, where can I find the info that you reported?) and may participate in changing controls and recording mileage. Again, though, I'd appreciate some simple instruction on using Vagcom to observe/record operating temperatures and, as mentioned again by Brian, recording fuel efficiency.

Nick, you can count on a contribution from me, if others are going to chip in. Dave.

 

[Variant TDI]

I can understand the skeptics wanting more accurate quantitation.

Althought the fuel guage is WAY off in terms of 7/8ths being 7/8ths... I've found it to be very repeatable in terms of how you've explained it.... as long as your fills are extremely consistant.

I know that mine can vary by as much as 1/4 gallon or more, depending on how patient/rushed I am to get the bubbles out, or how many people are behind me in line for the pump. 1/4 gallon is 10-15 miles of extra range.

 

[Nitrowolf]

What about filling up at 3/4 tank everytime to minimize the dead space inside the tank?

You'd have to meter out extra acetone to cover 1/4 tank instead of a full tank - does acetone stay completely mixed in the fuel, so that adding a fraction of a full tank amount will return a full tank to the proper ratio?

 

[Wonko the Sane]

I've found it to be very repeatable in terms of how you've explained it.... as long as your fills are extremely consistent.

I know that mine can vary by as much as 1/4 gallon or more, depending on how patient/rushed I am to get the bubbles out, or how many people are behind me in line for the pump. 1/4 gallon is 10-15 miles of extra range.

I agree with you, Variant TDI. More and better experiments can be done.

The great thing about technology today is that a group of strangers from around the country can collect and share data using instruments that the scientists at NASA in the 1970's could only dream of.

We now have the tools to prove/disprove the snake oil salesman's claims!

It seems like a nice long road trip on cruise control with an "Acetoned" tank and a VAG-COM measuring MPG may provide useful data. It should be noticeable if the beginning MPG is 10% to 20% higher and falls to a baseline value as the fuel is consumed.

Unfortunately, I don't have a VAG-COM. 'Anyone else feel up to trying it?

 

[Wonko the Sane]

What about filling up at 3/4 tank everytime to minimize the dead space inside the tank?

You'd have to meter out extra acetone to cover 1/4 tank instead of a full tank - does acetone stay completely mixed in the fuel, so that adding a fraction of a full tank amount will return a full tank to the proper ratio?

Hi, Nitrowolf:

I've thought about that.

If my theory is correct, after 5 or 6 gallons you've lost almost all of your acetone. You have to redose the entire tank. This eliminates any math. You could simply add 3 ounces of acetone everytime you top off your tank.

1. This adds more acetone costs to your fuel savings.
2. Some of us would be visiting the gas station every 3 or 4 days.

And we still haven't conclusively proved that the acetone helps.

 

[Dangerous_Dan]

Thermostats

I just pointed my web browser at a whole boatload of sites that sell VW parts. Most of them are in the "Sources for TDI parts at lowest prices!" thread ( Thanks BleachedBora ). I think GermanAutoParts.com listed the stock thermostat as the 87C, AutoHaus Arizona gave the switch temperatures, and also listed various thermostats available for VWs... yeah, just kind of un-official looking through the parts books...

 

[djmeier1]

acetone

This thread has been quiet for a week. Are we losing traction here...on both acetone and temp controls??? Dave.

 

[mrGutWrench]

This thread has been quiet for a week. Are we losing traction here...on both acetone and temp controls??? Dave.

__. I think that webehavin' far too much fun with snake oil!
'

 

[nicklockard]

Engine temperature sub-thread

I drained out 2.4 liters of coolant:

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And replaced it with 2.4 L of G12+ coolant I got from Herzogg-Meir VW dealer. ($18/gallon) My water/coolant ratio was previously 45/55.

This puts the balance toward more coolant. I hadn't been keeping close track of mileage before though, so I won't have numbers to show; but I can say that warmup time on my morning work commute is reduced by several minutes.

I'm also going to follow up by adding a higher temperature thermostat once the part number is located as others are doing.

 

[Cheshire Cat]

What about filling up at 3/4 tank everytime to minimize the dead space inside the tank?

You'd have to meter out extra acetone to cover 1/4 tank instead of a full tank - does acetone stay completely mixed in the fuel, so that adding a fraction of a full tank amount will return a full tank to the proper ratio?

I have had acetone mixed with deisel at 10X the rate in a glass jar (sealed) for several weeks with no seperation that I can see, re tank space, whatever the full to empty ratio it is always under vac, as they say in school "please discuss"

 

[LurkerMike]

You need a recirculation pump with a heater and a cooler to simulate what happens in a TDI fuel system. I suspect the fuel is heated significantly at the injector pump and cools in the return line and when it swirls and mixes into the fuel tank. This pressurization, depressurization, heating, cooling and general agitation of the fuel mixture needs to be approximated before any bench test can be used to accurately simulate what really happens in a TDI fuel system.

Simply placing whisky in the jar-o, won't tell you much more than the lyrics to an Irish ditty that Thin Lizzy covered and then Metallica covered that cover.

 

[djmeier1]

Yeah, but Chesire Cat should be complemented on trying to discover the rate at which acetone might evaporate out of a mixtyre with diesel fuel. The question is, what is a reasonably practical method of observing for that rate and drawing some conclusions?

 

[Cheshire Cat]

You need a recirculation pump with a heater and a cooler to simulate what happens in a TDI fuel system. I suspect the fuel is heated significantly at the injector pump and cools in the return line and when it swirls and mixes into the fuel tank. This pressurization, depressurization, heating, cooling and general agitation of the fuel mixture needs to be approximated before any bench test can be used to accurately simulate what really happens in a TDI fuel system.

Simply placing whisky in the jar-o, won't tell you much more than the lyrics to an Irish ditty that Thin Lizzy covered and then Metallica covered that cover.

I was looking at seperation, NOT evaporation otherwise I would have left the lid OFF

 

[djmeier1]

Okay, lets figure out a way to look at evaporation.

 

[elw459]

Yeah, but Chesire Cat should be complemented on trying to discover the rate at which acetone might evaporate out of a mixtyre with diesel fuel. The question is, what is a reasonably practical method of observing for that rate and drawing some conclusions?

It should be easy to put a measured amount of diesel in a graduated cylinder and add a measured amount of acetone. After a set period of time has elapsed, the total level of mixture should have decreased by the measured amount of acetone that was added. This should give a evaporation time frame. This ratio could be used to calculate the evap time frame for a tank of fuel. Keeping in mind this will be a static test. Maybe some type of agitator should be introduced into the test also.

 

[LurkerMike]

And heat and pressure?

My point is that the fuel system is soooo dynamic with many variables besides outside ambient temperature, g-forces induced by driving, accelerating, braking, turning, hitting pot holes and otherwise sloshing the fuel in the tank around...

There is the pump temp and pressure, the return line agitation, the vent or ventectomy, algae or lack thereof, the type and condition of the fuel filter(s) and probably several other factors that I don't even know about.

I can see how a static separation and/or evaporation test might reveal some properties of the mixture in the lab, but that would be only of minor interest to me when all the other variables are factored in a complete running fuel system.

Me? I don't want to shorten the lifespan of my injectors, injector seals, injector pump or even my fuel hoses. Not even for 5 more mpg.

In my ever so NOT humble opinion, I want to see it PROVEN that there is no damage to my TDI from the acetone FIRST, BEFORE we establish if there is any gain in mileage. I would rather waste time and money adding a totally harmless mileage placebo than to gain 20% better mileage that is gonna cost me $2k next year in parts and labor to get fixed...

I suspect that anyone who has an electric fuel pump submerged in the fuel tank like most fuel injected gassers (and maybe the PD's?) had better test the rate at which the acetone will dissolve the shellac from the copper wire windings in the fuel pump... just a thought... ;~)

 

[Fortuna Wolf]

I'll point out that acetone has an energy density of ~24.5 MJ/L versus gasoline's 32.9 MJ/L.

Anyhow, if the theory is that acetone acts as a cetane enhancer, why? Is it because its a highly volatile compound? What about using another volatile compound that's not so volatile or corrosive?

Anyone want to try mixing a gallon of gasoline into their diesel tank and report back? Use the lowest octane you can find.
Well, maybe try a quart first, and then work up from there.

I'm still experimenting with B100 and power service right now so it'll be a few months until I can work through 4 tanks of fuel

elw, did you just volunteer for a test?
Don't forget to run a control of just diesel. Mason jars and a sharpie should work fine.

 

[djmeier1]

I'll try ELW's experiment, but without agitation, next week and report back.

 

[djmeier1]

I'll try ELW's experiment, but without agitation, next week and report back.

I am renigging on this commitment. At a dosing level of 800:1, I don't believe that I could accurately dose a quart (or a gallon) much less measure the change in volume related to acetone evaporation. Plus, isn't there some rate of evaporation applicable to the diesel fuel itself?

I'm not learned in laboratory technique and don't feel that I could adequately measure such miniscule quantities using resources available to me. Sorry. Dave

 

[JettaJake]

Volumetric?! Evaporation rates?! Bah, fahgeddabowdit!

In my humblest opinion, surface tension is still the way to go.....best bang for the buck, best chance of getting discernable data, first pass anyway....

JJ

 

[nicklockard]

I am renigging on this commitment. At a dosing level of 800:1, I don't believe that I could accurately dose a quart (or a gallon) much less measure the change in volume related to acetone evaporation. Plus, isn't there some rate of evaporation applicable to the diesel fuel itself?

I'm not learned in laboratory technique and don't feel that I could adequately measure such miniscule quantities using resources available to me. Sorry. Dave

Dave, you nailed it.

JJ, care to do the surface tension measurements?

 

[Fortuna Wolf]

Does anyone think that gasoline as an additive is an idea with merit?

 

[nicklockard]

Does anyone think that gasoline as an additive is an idea with merit?

*polite cough*

[Sneeze/hack/cough]NO![/Sneeze/hack/cough]

...pardon me



But seriously, the VW engineers and manual writers are pretty explicit to not use any amount of any gasoline in a Tdi for whatever reasons. It has crummy lubricity, poor cetane, and less energy/volume. What was your hoped for benefit? I didn't follow that part of the thread closely enough.

 

[Fortuna Wolf]

I was thinking that gasoline being a VOC and distillage might be able to increase the cetane of diesel like acetone does (or so goes the theory). In addition gasoline probably wouldn't damage the plastics in our fuel system.

Acetone probably has worse lubricity and definitely has less energy than gasoline in addition to probably being more expensive and dangerous to work with.

 

[djmeier1]

Volumetric?! Evaporation rates?! Bah, fahgeddabowdit!

In my humblest opinion, surface tension is still the way to go.....best bang for the buck, best chance of getting discernable data, first pass anyway....

JJ

I'm still using acetone and still believing that I'm getting several mpg by doing so, but I really can't objectively show that to be true. That is frustrating to me...to say the least. Jetta Jake, maybe I should have been more receptive to your surface tension theory earlier. Would you explain, in layman's terms, how that is likely to give us reliable knowledge? Dave.

 

[LurkerMike]

I'm still using acetone and still believing that I'm getting several mpg by doing so, ...

What year, model and tranny?

How many miles are on it?

What mods?

Ever had any major engine service?

Any fuel component service?

Just wanting the full data set for maximum benefit from your noble ground breaking Guinna pig experiment.

 

[daBooj]

so... tested the surface tension with a Krüss K-100, ran it 8 times. 2 regular D2, 6 with acetone. 4 of those being 0.16% acetone, 2 with considerable higher acetone concentrations (ie. added a small squirt to the 50mL dish)

Was using the plate method.

*Regular D2 came in at ~27.5

*the first run with acetone started out around 29 and dropped to about 25, but we could not repeat this run with fresh diesel-acetone mixtures (and I didn't set it up, I assume the plate wasn't clean and foam was breaking).

*All other runs with acetone in the diesel fuel were within the high and low of the regular D2, there was no difference in surface tension. The runs with acetone were closer to the mean value of regular D2 and were quite repeatable.

Now, I'm not an expert with the instrument yet. I may need to repeat this test later once I become more aquainted with the instrument. But we were getting exactly the right numbers for water, and the results for the diesel were repeatable. We saw no difference in the surface tension after addition of acetone.

(Sorry I don't have pretty pictures, but I don't have a good way to get my results off of the computer yet. When I do, I will probably run this over again and post pretty pictures for you.)

 

[djmeier1]

my rig

What year, model and tranny?

How many miles are on it?

What mods?

Ever had any major engine service?

Any fuel component service?

Just wanting the full data set for maximum benefit from your noble ground breaking Guinna pig experiment.

2002 Jetta 5-spd. Upsolute, .205 injectors, head studs, clutch upgrade, .681 5th gear and a few other inconsequential items. 112,000 miles and no major engine or fuel system service performed.

I see only minimal risk in acetone addition, but also only minimal probative value to the data obtained. I don't expect to report back unless something very interesting should occur. Dave.