Hello there and welcome to the BMW Car Club of America.

If you are a BMW CCA member, please log in and introduce yourself in our Member Introductions section.

Dipetane... any experience?

Discussion in 'Diesel' started by cwbiii, Dec 31, 2010.

    cwbiii guest

    Post Count: 160
    Likes Received:0
    This additive claims 8-12% mpg gains. Its been in use a long time but there isn't much reliable user info on it so I can't determine its SOI (Snake Oil Index).
    I'm planning to "test" it for a while and see if it can live up to its hype.
    I put in a inquiry to BMW whether or not it is ok to use in my 335d... I got back a "check with your local service representative" so I'm going to do that in the near future.
    I need to go through at least 3 tanks of unadulterated fuel as a baseline anyways.
    My first half tank was spot on 30mpg for my normal driving. I'm off this week so I won't count it and refill the tank on Sunday to start my 3 tank average, 1 tank each week. Three tanks is about 1200 miles so I expect that they will be around 13 gal per fill up.

    Then I will add the recommended amount for my 16gal tank and start a 3 tank average with the additive.

    Burn a tank of fuel to deplete the additive and then start the process over again. This should yield a fairly valid result. I will publish those results here as I finish them. I would still like your input if you have anything useful to share.

    My driving is a mix of about 10 miles rural and 56 miles highway daily.
    Rural is 30-40 mph with a few stops, lights and on/off ramps, highway is 65-85 mph. (I have my speed limit warning set to 85mph since this is the edge of what is "allowed" here) I try to stay within 5mph of the posted speed off of the highway.
    I like my accelerator... and drafting on the highway. I hate to use my brakes on the highway and avoid as long as I can. My average speed for the 33 miles to/from work is 55/60 mph... but around mid 40's to low 50's for the week/tankful.

    My prior experience with my 7's is that the computer lies to you if you try to "conserve" it tells you that you are, but the actual data says that it is pretty much the same regardless of the driving style unless you are unusually heavy of foot.

    Typically the computer says I'm getting a couple more mpg than I am, the discrepancy gets considerably larger when I try to drive conservatively.
    It's one of the things I check in my vehicle spreadsheet.
    Caveat;
    Since this is my first 3 series then it may perform differently than my 7's did.
    I know that over 190k miles in 2 different 7's I averaged 19.2 for the 740 and 19.8 for the 750. 151k/43k respectively.

    Chuck
    • Member

    Peef

    Post Count: 4
    Likes Received:0
    My gas cap (diesel cap?) specifically states "no additives"; I'm kind of surprised BMW didn't stick to the party line here. I also subscribe to the old adage "if it sounds too good to be true, it probably is", but I concur with your test method as long as your driving habits remain consistent. My driving patterns are so variable I wouldn't even attempt it.

    I will tell you that I have found my car's MPG calculation to be within 0.3 of what I calculate on my spreadsheet. I'm averaging just over 33 for the 6000 miles I have had the car. Can't complain at all about that.

    ForcedInduction guest

    Post Count: 358
    Likes Received:4
    Most car makers tell you in the OM do not use any oil or fuel additives. The reason is obviously because most are snakeoil and can actually damage the engine. It's very easy to get duped by bogus ad claims.

    In my experience with BMW "customer interactive specialists", they seem to have no clue what so ever about the product. They appear to type in a couple search words and regurgitate whatever is displayed on their PC monitor in India or whatever off-shore support site that BMW is using for customer relations. I've even seen them give incorrect engine oil requirement information to owners in other BMW forums... :(

    cwbiii guest

    Post Count: 160
    Likes Received:0
    Haven't had that conversation yet...

    I have a service scheduled for this upcoming Wednesday and plan to ask then
    since I'm waiting around for it anyways. I've ordered the Dipetane, but I can always use it in my diesel motor home and tractor if my BMW rep says no. But it will be a bit harder to tell if I'm getting a mileage increase in either of those because of the variation in use that I give both of them. I do have good records for the MH and will be able to tell if it gets noticeably (greater than 5%) better power or performance. It's going to take a bit longer since my car is going into the body shop to fix the branch damage and I'll be without it for a it over a week.

    I'll find out soon...

    Chuck
    • Member

    Pyewacket1

    Post Count: 271
    Likes Received:5
    I'm with you on this.

    If an additive existed that really worked without causing any unwanted "side-effects", manufacturers would be all over them and encouraging their customers to use them.

    Think about it for a second... If an aftermarket additive could invcrease mileage, and not cause problems, ANY manufacturer would be making mileage claims based on the increased mileage induced by the additive.

    IMO, especially if a car is under warranty, I would be highly unlikely to even test out an additive without (at a minimum) the signed suggestion of my local dealer stating they had no problem with the additive.... and, we all know how easy that would be to obtain...

    Here is one of my favorites...They sell them at Best Buy...

    http://www.crunchgear.com/2010/02/2...mething-that-plugs-into-your-car’s-dc-outlet/

    ForcedInduction guest

    Post Count: 358
    Likes Received:4
    P.T. Barnum would smile... :rolleyes:

    cwbiii guest

    Post Count: 160
    Likes Received:0
    I got the OK.

    I got a verbal OK to at least try a few tankfuls to see if it lives up to its hype or not.
    Since it is not supposed to be anything that is not already in common Diesel fuel then it should not cause any warranty issues.
    Could it work? of course it "could"... I see repeatable mileage differences between summer and winter mix fuels so the blend of hydrocarbons in the fuel definitely makes a difference. I know that the biggest difference between summer and winter diesel is the amount of dissolved paraffin in the blend. They take more of it out in the winter to keep the fuel from gelling... and this reduces its energy content per unit volume. I intend to place a gallon of this stuff where it gets really cold outside and test its viscosity before I even think about putting it in the tank... I definitely don't need gelling problems.
    Gasoline winter blend uses a higher percentage of volatile hydrocarbons which also has a lower energy content than summer mix.
    I'm currently hovering in the 29-30 mpg range for my normal driving. I have to say that the on board computer in this vehicle appears to be more accurate than the ones in any of my prior BMW's... but it still may be a bit early to say for sure since I
    have only a bit over a tank and a half to average with. I'll need a dozen tankfuls to make that declaration for certain.

    Chuck
    • Member

    Satch SoSoCalifortified

    Post Count: 2,187
    Likes Received:64
    What a comedian!!

    Chuck say:



    Useful? On an Internet forum?! WHAH!
    • Member

    tiFreak

    Post Count: 523
    Likes Received:2
    let's post cat pictures instead! :D

    [IMG]

    cwbiii guest

    Post Count: 160
    Likes Received:0
    more...

    My cars in the shop for bodywork... I'm missing it badly! I have a Dodge
    rental instead... boo-hoo, I guess I'm doing penance.
    The Dipetane came in...I opened a container and checked it out.
    It is an odorless clear liquid with a slightly oily "feel" similar to mineral
    oil. It certainly doesn't smell anything like "fuel". I figure it will be another
    month or so before I get to try it for the first time.
    My first official tankful without was 13.48 gal/400 miles = 29.67 mpg, the on board
    computer said 30.1 mpg for a delta of +0.43 mpg... pretty close.
    The Dipetane was $110 for 4 gal... about the same as synthetic oil.
    At 200:1 mix ratio that adds up to $0.14 added to the price of each gallon of diesel
    fuel. I'm currently paying $3.45 per gal. That adds up to a 4% increase to break even. I spent another $60 for containers and a couple of accurate graduated cylinders for dispensing the Dipetane.
    Its going to be another week or so before I get my car back from the body shop... the branch did more damage than I saw, they had to put in an additional claim once they got it clean of the effects of winter. Now it includes dings to the roof, trunk lid, and a couple of bumpers. At least it will be as pretty as new when I get it back.
    wanna take a peek at the progress?
    http://www.wagnercertifiedcollision.com (auto watch portal) vehicle #627

    Till next update...

    Chuck
    • Member

    Pyewacket1

    Post Count: 271
    Likes Received:5
    I'll give you credit for having guts...

    As expensive as an engine repair might be as compared to the relative small savings this product has to offer (unless you really put on tons of miles), I wouldn't have the courage to try it in MY vehicle....

    But, I must say I am a bit intrigued by your "experiment", so please keep this thread updated.

    Good luck with your test as well as getting your car repaired soon. Surely driving a Dodge rental must feel like a huge let-down...

    Addendum: Went to the repair site. That's pretty neat that you can track you car's progress through the repair cycle.

    cwbiii guest

    Post Count: 160
    Likes Received:0
    other car...

    If it was summer, I could use my wife's 330i convertible... but right now its
    all under cover with the battery disconnected (though within reach of the tree that nailed me). There's another 325i parked right next to it waiting for some mechanical attention that is not forthcoming any time soon.
    Not to come out until well after the last snow flies. She won't let her convertible see any salt, and my son needs to spend some serious wrench time with the other to make it capable of passing an inspection... it still has Florida plates(tags) on it from when he moved back up here last year. There's a serious lack of cash since he and his wife decided to both go back to college. (It's a wise move all the same!!!)
    I'm feeling some of the cash crunch myself so I'm also looking at ways to reduce my
    expenses here and there. I hadn't really planned on replacing my car so soon, but when the transmission in the 750 started to act up with only a couple months left on the extended warranty I decided not to chance it. Most of the savings is in fuel expenses though as I still was a bit below water on the 750 and carried that into the new loan. This new vehicle needs to go 200K+ like my prior 740 did.
    Everything I've been able to find and verify about the Dipetane says that it extends the life of engines by reducing wear in addition to the added fuel mileage so I'm willing to verify the part that I can easily and then make a decision about using it after that based upon the results. I have yet to wear a BMW engine out before the body anyways... and with all the electronics in cars today I expect that the electronic gremlins are likely to grind it to a halt before the mechanical one's do. I used to be able to fix the electrical/electronic systems in my older BMW's but these new ones simply require replacement when they foul up. I keep wondering about collector cars in the future, it will be a lot more costly to maintain today's vehicles in working condition when they get to be 25+ years old... it gets very tough to re manufacture electronics for such old systems... just look at how difficult it is to fix a 7 year old computer.

    Chuck
    • Member

    lkchris

    Post Count: 47
    Likes Received:0
    Isn't this a case of basic physics, or thermodynamics, or the like?

    Something that's a fuel additive is going to have to change the basic power content of the fuel in order that the vehicle will now do the same amount of work using less fuel. Right? What else is there?

    This really should mean that the engine when put on a dyno should show a power increase.

    Sounds like this stuff should be as dangerous to handle as maybe liquid plutonium.

    cwbiii guest

    Post Count: 160
    Likes Received:0
    Basic claim

    It's basic claim is that it helps the fuel burn more completely. If so then that is where the energy comes from. Its energy quotient is slightly higher than diesel fuel, but not enough to make the kind of difference they claim. If the BMW diesel engine is burning the fuel completely as a design feature then this stuff will have no advantage.
    The proof (either way) will be in the testing and I'm committed to giving it a fair shot.
    I really don't know what to expect but I am intrigued by what data I have been able to hunt down. It seems to act as advertised in some applications. The question for me is will it work as well in what I believe is already an efficient engine design?
    I have found out enough information that I could probably make a fair guess at its chemical composition... even though it is a "trade secret" as marked on the bottle.
    In the various literature I found a C-H ratio in percentage, plus the above energy quotient which was also published elsewhere. With these two pieces of data I can
    use basic chemistry to extrapolate a basic chemical formula (like C4H10 for instance) and the energy that binds them... and backtrack this to the a likely hydrocarbon formula. The name may also provide a clue, though it could have also been chosen to mislead... as it is not accepted naming nomenclature for a hydrocarbon compound. Di means a pair, Pent means 5, Taine is a long chain hydrocarbon ... so the name suggests C2H5.
    Dipetane sounds similar to Di-Pent-Taine.

    Caveat:
    This is my recollection, probably not entirely accurate since it has been 30+ years
    since I studied Freshman chemistry in college.

    Chuck

    cwbiii guest

    Post Count: 160
    Likes Received:0
    quick results...

    I ran 1 tankful and have been thinning it about half with each fillup... so far the results do not look very promising. Too much variation in mileage to see anything significant as of yet. My test volume is around 9 gal for this test which is quite small... and the error at fill ups could be a couple pints... approx a 2-3% error to begin with.
    I did this to see if there was anything statistical standing out and to see how mileage changed as the ratio changed. Quick results:

    Dipetane ratio 106:1 178:1 317:1 525:1
    fuel 9.22 9.59 9.02 9.72
    miles 290 299 285 288
    mpg 31.5 31.2 31.6 29.6
    bc mpg 30.9 31.7 31.3 30.9
    Delta -0.6 +0.5 -0.3 +1.3
    avg speed 49.7 55.4 53.7 39.5

    What I consider a valid result has to have a avg speed between 45 - 55 mph,
    so the last result is outside of that range... and the 2nd is just outside the high
    so technically should be thrown out as well. Even so, the low to high actual difference is only 2 mpg, the average is 31. The bc's average is 31.2 which correlates pretty well with the actual average mpg though it swings less while the delta is actually more significant at about 4%, still quite good in the scheme of things.

    One thing I have noticed with the bc mpg data is that humidity seems to alter the fuel mileage significantly... when the humidity is near 100% I get the best fuel mileage of around 36mpg for a one way trip to or from work. I would probably need to rig up some kind of water injection to test that for real.

    The bottom line is that it is still too small of a sample.
    I'm having a difficult time getting results that fit within the valid window because of weather, traffic, temperature and use variations...Snowstorms in particular played havoc with the real data. I will get what I need eventually for a real world test... I'm still working on it. I'm going to go back to 14+ gal fill ups after I run this tank down and start the baseline test again now that the weather seems to have stabilized.
    I've also developed a method to reduce the variation in filling up... since the diesel fuel foams so much I count to 20 after I stop filling the first time and then top off.
    I have to use the filler tube where I fuel up and the auto stop does not work with it... so I have to listen carefully and stop before it overfills. It's really a pain if I have to use the large "truck" nozzle since it cannot handle the volume it can deliver.


    Chuck

    cwbiii guest

    Post Count: 160
    Likes Received:0
    The verdict is in... Snake oil.

    Well the comprehensive test is in and the average mileage difference between with and without dipetane was insignificant. 6 tanks of fuel for each (2500+ miles each) and a .09 mpg difference. The only thing it may do is perform slightly better... so I may use it in my tank when I autocross.

    w/o dipetane 79.09 gal fuel, 2502 miles 31.63 mpg.
    with dipetane 87.12 gal fuel, 2748 miles, 31.54 mpg.
    • Member

    Pyewacket1

    Post Count: 271
    Likes Received:5
    As we posted on Jan. 8, if the product performed as claimed it would be recommended by auto manufacturers.

Share This Page