Quantcast

Acetone in your gas tank = more MPG???

Discussion in 'The Lounge' started by Curb Hucker, Nov 30, 2005.

  1. Curb Hucker

    Curb Hucker I am an idiot

    Rep/Likes:
    4 / 0
    Joined:
    Feb 4, 2004
    Messages:
    3,661
    Location:
    Sleeping in my Kenworth
    This is take from a post in a land rover forum:
    _____________________________________________
    Well, damn GP, that's about the most coherent thought I've heard from you since you pulled the Jag tail lamps outta your ARB.

    FWIW, I started an Acetone experiment a couple of months ago on the D2.

    I'm running between 8-10oz per full tank (24gal), sometimes a little less acetone. Truck specs:
    99D2, 88K miles, orig O2 sensors
    PowerChip
    STI plug leads
    Bosch Plat (2)
    Safari Snorkel
    4.11 gears
    3" RTE lift
    285/75-16 on stock alloys
    Warn 15K, RTE sliders/bumper, Greg Davis rear bumper, Engle and full pelican are always in the truck.

    I'm an easy driver with the right foot and rarely exceed 75mph on the hwy.

    NO ACETONE, country roads, town driving, pre-MAR:

    264 miles/19.5 gal = 13.54mpg
    292 miles/19.7 gal = 14.82mpg

    This was around MAR and right about here, I put in new plugs and wires (Still no acetone):

    322 miles/20.7 gal = 15.55mpg (about 85 miles here was hwy)
    319 miles/19.9 gal = 16.03mpg (about 90% hwy miles here )

    WITH ACETONE, 80% hwy / 20% city (Knoxville, TN)

    348 miles/20.3 gal = 17.14mpg
    369 miles/20.7 gal = 17.83mpg
    358 miles/19.7 gal = 18.17mpg

    I'm driving around 70mph on the hwy and I only use the cruise on the areas up here on 81 where it's flat. This was my second trip to Knoxville.

    336 miles on 20.3 gal with a 15knot direct headwind down 81S running 75mph all the way
    Back last night, last two tanks of the weekend:

    311 miles/20.3 gal: ~15.32mpg, 90% city driving, NO Acetone ( I forgot to put it in)
    375 miles/21.5 gal: ~17.44mpg, 85% hwy driving, 8oz Acetone, tried to keep it under 75mph.
    334 miles/20.3 gal: ~16.5mpg, about 50/50 hwy/city (ran 75-80 on the hwy mostly)
    _______________________________________________

    Has anyone else put acetone in with their gas? It seemed to help this guy and a few others out quite a bit.
     

    Please register to disable this ad.

  2. PatBranch

    PatBranch Turbo Monkey

    Rep/Likes:
    8 / 7
    Joined:
    Sep 24, 2004
    Messages:
    10,461
    Location:
    wine country
    Sounds crazy, but its working. Acetone is about 3/4 isopropyl. I read a while ago that its used in rocket fuel.

    Thase are some good increases. I wonder how it affect performance (torque,acceleration,top speed, reliability?
     
  3. BigMike

    BigMike BrokenbikeMike

    Rep/Likes:
    5 / 0
    Joined:
    Jul 29, 2003
    Messages:
    8,933
    Location:
    Montgomery county MD
    I've heard of this also, but i'm scared to try it. If I had some old beater than maybe, but not in my pretty new (to me) Pathfinder :blah:


    I've heard a lot of reasons it works, it has somthing to do with breaking the surface tension of the gasoline and using it all, instead of wasting some........ somthing like that
     
  4. Toshi

    Toshi Harbinger of Doom

    Rep/Likes:
    180 / 1,326
    Joined:
    Oct 23, 2001
    Messages:
    24,477
    i'd like to see a systematic study of this, not 3 tanks on uncontrolled roads with variable driving style (influenced by the "study" not being blind at all), weather (temperature!), fuel cutoff on the pump at the station...

    i'd also like to see verification of this surface tension claim. fwiw a thread on nasioc (the subaru board) stated that gasoline already has negligible surface tension. from a handwavy perspective this seems plausible -- after all, why do you think gasoline fumes are so widespread at the pump if not for the volatility? (might be conflating unrelated concepts here, but i'll defer to the professional chemists :D)

    the final thing i'd like to see is whether adding 2 or 12 oz of anything to a full tank has any effect at all beyond the placebo influence on driving style. :D
     
  5. Curb Hucker

    Curb Hucker I am an idiot

    Rep/Likes:
    4 / 0
    Joined:
    Feb 4, 2004
    Messages:
    3,661
    Location:
    Sleeping in my Kenworth

    Well I can tell you one thing, there is NO way to pull 17-18mpg out of one regular tank of gas on one of these trucks no matter how you drive, trust me, I know :dead:
     
  6. Toshi

    Toshi Harbinger of Doom

    Rep/Likes:
    180 / 1,326
    Joined:
    Oct 23, 2001
    Messages:
    24,477
    there are still way too many variables. i bet temperature affects the auto cutoff on the gas pump, for instance...
     
  7. PatBranch

    PatBranch Turbo Monkey

    Rep/Likes:
    8 / 7
    Joined:
    Sep 24, 2004
    Messages:
    10,461
    Location:
    wine country
    Someone should do it on a dyno. Does anyone here have a dyno?
     
  8. firetoole

    firetoole duch bag

    Rep/Likes:
    4 / 0
    Joined:
    Nov 19, 2004
    Messages:
    1,910
    Location:
    Wooo Tulips!!!!
    how is this worth it 1 gallon of acetone costs about $10.00
     
  9. C.P.

    C.P. Monkey

    Rep/Likes:
    6 / 8
    Joined:
    Jan 18, 2004
    Messages:
    558
    Location:
    SouthEastern Massachusetts
    No mention what effects this might have to the cat. converter & the rest of the emissions system...
     
  10. Transcend

    Transcend My Nuts Are Flat

    Rep/Likes:
    5 / 0
    Joined:
    Apr 18, 2002
    Messages:
    18,062
    Location:
    Towing the party line.
    exactly. Acetone is far from cheap, is highly explosive (more so then gasoline) and works REALLY well to strip just about anything gunky off of anything shiny. :)
     
  11. MMike

    MMike A fowl peckerwood.

    Rep/Likes:
    61 / 84
    Joined:
    Sep 5, 2001
    Messages:
    18,261
    Location:
    just sittin' here drinkin' scotch
    You may be onto something right there. Maybe the acetone just cleaned out the accumlated gunk in the fuel system!
     
  12. DRB

    DRB unemployed bum

    Rep/Likes:
    5 / 0
    Joined:
    Oct 24, 2002
    Messages:
    15,287
    Location:
    Watchin' you. Writing it all down.
    Its probably either a car salesman or a garage owner looking for folks to complete f' up their cars so they need fixing or replacing.
     
  13. N8 v2.0

    N8 v2.0 Not the sharpest tool in the shed

    Rep/Likes:
    17 / 149
    Joined:
    Oct 18, 2002
    Messages:
    11,008
    Location:
    The Cleft of Venus
    Acetone in your gas tank = big MFE?!!!
     
  14. ummbikes

    ummbikes Don't mess with the Santas

    Rep/Likes:
    5 / 0
    Joined:
    Apr 16, 2002
    Messages:
    1,795
    Location:
    Napavine, Warshington

    That is my bet too.
     
  15. PatBranch

    PatBranch Turbo Monkey

    Rep/Likes:
    8 / 7
    Joined:
    Sep 24, 2004
    Messages:
    10,461
    Location:
    wine country
    So it miight be good to do every month or so.
     
  16. Transcend

    Transcend My Nuts Are Flat

    Rep/Likes:
    5 / 0
    Joined:
    Apr 18, 2002
    Messages:
    18,062
    Location:
    Towing the party line.
    Ya that's a good point. Acetone is pretty nasty stuff. When it gets really cold out, i use it to light my woodstove. It burns hot enough to force all the cold out out of the chimney and I don't get smoke in the house.
     
  17. Wumpus

    Wumpus makes avatars better

    Rep/Likes:
    29 / 153
    Joined:
    Dec 25, 2003
    Messages:
    8,170
    Location:
    Six Shooter Junction

    Water has high surface tension but evaporates readily.
     
  18. urbaindk

    urbaindk The Real Dr. Science

    Rep/Likes:
    4 / 0
    Joined:
    Jul 12, 2004
    Messages:
    4,831
    Location:
    Sleepy Hollar
    Interesting. I'm a chemist (actually materials engineer but close enough). I was trying to look up some data to shoot this acetone idea down but didn't really find anything definitive against it.

    From a chemical point of view acetone has some good properties. In gasoline (spark driven) engines we are looking for a high autoignition temperature and a low flash point. Basically you want the fuel to vaporize in the combustion chamber and not ignite before the spark plug fires.

    Here are some numbers:

    octane (not really gasoline but close enough)
    Flash point: -45 C
    autoignition temperature: 257 C
    vapor pressure @ 25 C = 13.95 mm Hg

    acetone
    Flash = -18 C
    autoignition = 538 C
    vapor pressure @ 25 C = 229 mm Hg

    Ok so based on these numbers, I've come up with the following conclusions.

    Adding acetone should ignite similarly to gasoline. It wouldn't pre ignite due to it's high autoignition temperature and as such might limit knocking and pinging somewhat.

    With its (very) high vapor pressure one might expect that it would vaporize more easily than gasoline which should make it burn more efficiently and evenly in the combustion chamber. I suspect that this effect would be negligible with modern fuel injector systems though.

    Acetone would have a slightly lower fuel value (energy/mass) than gasoline. Its chemical formula contains some oxygen and as such is already in a slightly oxidized state from the get-go. (combustion = oxidation). This might cause horse power to suffer somewhat.

    I suspect the main issue regarding its use as a fuel boils down to (no pun intended) its terribly high vapor pressure / volatility. It's just not safe to have a whole lot of it stored up in your gas tank.

    Also not mentioned is that it is a damn fine solvent and would probably eat rubberized fuel lines over time.
     
  19. rooftest

    rooftest Monkey

    Rep/Likes:
    0 / 0
    Joined:
    Jul 10, 2005
    Messages:
    612
    Location:
    OC, CA
    Wouldn't using a less efficient fuel make your milage per gallon decrease?
     
  20. urbaindk

    urbaindk The Real Dr. Science

    Rep/Likes:
    4 / 0
    Joined:
    Jul 12, 2004
    Messages:
    4,831
    Location:
    Sleepy Hollar
    You would think so wouldn't you?
     
  21. BigMike

    BigMike BrokenbikeMike

    Rep/Likes:
    5 / 0
    Joined:
    Jul 29, 2003
    Messages:
    8,933
    Location:
    Montgomery county MD

    Yes, I would. :)

    So whats the REAL difference between higher octane fuel and lower octane fuel?
     
  22. Wumpus

    Wumpus makes avatars better

    Rep/Likes:
    29 / 153
    Joined:
    Dec 25, 2003
    Messages:
    8,170
    Location:
    Six Shooter Junction
    20 cents per gallon
     
  23. urbaindk

    urbaindk The Real Dr. Science

    Rep/Likes:
    4 / 0
    Joined:
    Jul 12, 2004
    Messages:
    4,831
    Location:
    Sleepy Hollar

    Wumpus is pretty much right. From what I understand it's a bunch of hooey.

    Petrol engineers came up with a nifty way to compare fuels. You and me call it the octane rating system. Take your good old 87 octane gasoline. It is formulated with lots of various additives and other junk to run in a test engine like a mix of 87% 2,2,4 methylpentane (they call it octane and it has same chemical formula but different structure than octane) and 13% heptane.

    2,2,4 methylpentane has very good running characteristics, no knocking, pinging or any of that. Heptane runs like absolute crap, knocks like crazy, etc.

    Anyway. The petrol engineers come up with these formulations that match the running characteristics on their test engines and that's how we get octane ratings.

    Now, comes along the auto engineers. They design really live put'em in your truck and drive around town engines (not test engines!!!) These folks being pretty smart people design their engines so that run optimally at 87 octane. No knocking no pinging, just smooth running engines.

    So basically anything above 87 octane (unless your engine specifically requires it) is a waste of your money and may actually cause harm. Higher octane rated fuels tend to burn hotter and over time this can damage the engine.
     
  24. justsomeguy

    justsomeguy Monkey

    Rep/Likes:
    0 / 0
    Joined:
    Oct 3, 2005
    Messages:
    723
    Some would argue that the premium blends can be beneficial due to superior detergent additives. Some would argue that the better detergent claim is marketing hooey.

    Cars can still use gas with an ocrtane rating that is lower than the recommended rating but the ECU will retard timing and you'll be getting less power.

    Re: Additives

    In areas where high octane (93 or 100) fuel isn't available you can use an octane booster (no, not the crap found at auto parts stores, I'm referring to Toluene) to get to the desired octane. That is if you're willing to mess around with rubber gloves and be willing to be suspected of running a meth lab every time you buy it in quantity.