Archives

I ordered a small bottle of a polyisobutylene additive (Viscon) to give it a thorough test. I've done a fair amount of research on it over the weekend and the theory makes just enough sense to warrant trying it. One reference seems to indicate that California puts this stuff in the fuel to reduce emissions, which lends it some credibility. (At least I know it shouldn't hurt anything.) But of course the big question is if it can do anything for fuel economy on a modern fuel injected car that has to burn Connecticut's ethanol/gasoline mix.

It's going to be a little tough to negotiate the transition from winter fuel to summer fuel since I don't know exactly when that occurs. I plan to avoid confounding the experiment too badly buy running 2-3 tanks on/2-3 tanks off for at least 2-3 cycles over the next several months. With that much data I should be able to isolate the one variable fairly well if the results are significant. I'll keep track of everything on my GH fuel log (same username).

Isn't PIB another name for synthetic rubber?

I suspect its use in fuel is purely as a detergent- but your engine is already pretty scrubbed out from the constant ethanol in your fuel, so benefit = ??

Butenes by themselves are used industrially to produce pure octane by dimerizing. This of course increases the octane rating of fuel...but octane has little to do with MPG for an engine designed around 87.

Still, can't hurt. Just like MMT or acetone...

That's correct, PIB is butyl rubber. The theory behind PIB, which appears to come from some legitimate research, is as follows: Gasoline contains distinct hydrocarbon components of varying molecular length. These tend to separate as the fuel enters the combustion chamber, resulting in an uneven distribution of fuel. The shorter hydrocarbons combust first, followed by the longer-chained hydrocarbons which tend to clump together in larger droplets.

Very small concentrations of PIB (10-50ppm) serve to homogenize the fuel in the intake charge by helping the short-chained hydrcarbons hang on to the longer-chained hydrocarbons just a little bit longer. In theory, this produces a more uniform burn (for more complete combustion) that doesn't last quite as long (for reduced NOx and slightly higher MEP or mean effective pressure-a measure of work produced by the cylinder). That increased MEP means that you are making more power with the same fuel and can back off the throttle.

So is it hogwash? Who knows. I don't question the effect of PIB on droplet formation so much as I question whether slightly more uniform droplets can make a measurable impact on fuel economy. Guess I may as well find out!

keep us updated!

Hi Brick:

___I covered most of my thoughts (rants ;)) in the other Vapor injection thread but why not first start receiving excellent FE without modification before you being any experimentation with additives like PIB or the Torco concoction to name just 2 that some hang their hat on? Until you come close to the limits of your ability in a given automobile, any improvement may be due to your increased FE prowess rather then the additive(s) themselves.

___Good Luck

___Wayne

Wayne- I hear your comments and understand what you are saying. The problem with most average consumers who try these things is that they don't care to actually test the product. They prefer to add it, look at a number, and say "Look, it works!" Not the case with me :) I am testing this product because I want knowledge, not because I am convinced that it will magically reduce my gas bill.

You are right that improving FE through driving methods is the best way to go, and any gains on a given tank could be due to that or any number of other factors. But that's where careful experimental design comes in. Alternating 3 tanks on/3 tanks off for many, many tanks is the only way to produce enough data to be significant. From that, any significant changes should show themselves through statistical analysis. And if nothing comes out of the noise I'm only out $25 and might be able to save others some money.

Besides, I don't get to do much in the way of hard engineering on a day to day basis. I need to do some experimentation to keep my brain from going completely to mush. ;)

I would be very interested if you would keep careful notes and compile it into an article. This is one of the things I wanted to do with this site. Do testing on products to see what they do or don't do. Like you said, when people use these products they are looking for an improvement so they might be a bit biased. I think a nice long term test is great.

Hi Brick:

___As Tom mentioned, we have talked about HW and additives to get the real scoop other then the “stuff” posted on the Internet. I cannot wait to hear your results and if PIB, Torco, Acetone, TX-7, and whatever else comes out of the closet, at least we will know you are doing a heck of a job of sorting out the fluff from the actuals. This could end up being exciting ;)

___An interesting read from a while ago may shed some light on the subject as well. Take a look near the bottom to Pat Goss’ comments about the issue. If you cannot view the link, some pertinent information is posted below.

Caught Over a Barrel (http://www.washingtonpost.com/wp-dyn/articles/A64180-2004May3.html)
Gas Gimmicks

But then high gas prices are known to fuel absurd ideas.

How else to explain increased sales of so-called gas-saving devices claiming to boost miles per gallon?

"Buyers really need to beware of these claims," says Chris Grundler, chief executive of the Environmental Protection Agency's National Vehicle and Fuel Emissions Laboratory in Ann Arbor, Mich. "We have tested over 100 of these over the last 20 or so years and have found that very few of them provide any fuel economy benefits. Those that did were marginal."

The hot fuel-saving technology this year is called the "Tornado." For $69, this air-swirling gadget installs in a car's intake and, supposedly, creates a "vortex" of air that results in more efficient combustion. Its ads say tests show the Tornado increases mileage from 11 percent to almost 29 percent.

Sound too good to be true? "Nobody can believe this!" says Jay Kim, president of Tornado Air Management, in Santa Fe Springs, Calif., the manufacturer.

Kim says sales are up like never before: "A lot of consumers just love it. Tens of thousands of them."

But the government doesn't love it. The EPA has tested similar air-moving gadgets and none worked. The agency evaluated the Tornado's data and found no reason to think it can improve fuel economy, says spokesman John Millett.

Automotive expert Pat Goss, who hosts "Goss's Garage" on WJFK-FM and NewsChannel 8 and is a regular on PBS's "Motorweek," has tested more than a thousand fuel-saving devices over 25 years at his auto repair business in Seabrook, including earlier and current versions of the Tornado. The best it tested was a 0.6 mpg increase; the worst, a decrease in fuel economy.

"We get these things all the time," says Goss. "Not one of them that we ever tested did anything significant."

Kim dismisses the EPA's remarks as a "big government thing. Nothing you can do." Goss's findings? "Hmm, really?" he says.

Another device called the FuelSaver-Pro promises to save up to 27 percent in fuel economy by realigning gas molecules using magnets boxed around the fuel line. Mark Ayoub, who markets the product on FuelSaver-Pro.com, says, "Sales have increased since gas prices have recently shot up."

But the EPA in November alerted the Federal Trade Commission that the maker of the $89.95 FuelSaver-Pro was making unsubstantiated claims by mixing results from different tests to boost its mileage claims.

The manufacturer, IRD International Research & Development in San Diego, did not reply to requests for interviews, but the FuelSaver-Pro Web site just changed its promotion.

Roger Crawford, a businessman and independent researcher in Midland, Tex., takes a different approach to fuel economy. He has just begun marketing a gas additive he calls "XtraMPG." He says it boosts octane, burns cleaner and enables motorists to get better fuel economy and buy less expensive grades of gas -- saving 10 to 15 percent overall on gas.

What's in XtraMPG? "Most of us know it as nail polish remover," Crawford says. "It is simple acetone, a nonhazardous organic chemical . . . rated at 150 octane."

Crawford says he'd be happy if everyone bought acetone and added it to their gas tanks. But since people seem reluctant, he's packaging it as XtraMPG.

The EPA hasn't tested XtraMPG. But the EPA's Chandler warns that consumers need to beware what gadgets and fuel additives they add to their cars -- especially with today's computer-controlled fuel-injection systems. "There are other, more practical ways to save fuel," he says.___Good Luck

___Wayne

Hi Brick:Until you come close to the limits of your ability in a given automobile, any improvement may be due to your increased FE prowess rather then the additive(s) themselves.

___Good Luck

___Wayne

Hey Brick,
I want to echo what Wayne has said. Until you have perfected your technique, testing FE enhancement products will be a waste of time. Your interest in having positive test results are likely to become a self fulfilling prophecy. This happened with my del Sol. Even after hypermiling the Prius and the Outback, I found that I still had something to learn with the del sol.

After my fiirst tank which was about 50.3 MPG, I was convinced that I had hit "the wall" at 30-35F average temps. So I began adding acetone, 3oz/10 gals. In each subsequent tank I have raised my FE, 51.0, 51.8 and 52.0. I was starting to think that acetone actually made a difference. But before I made any sort of proclamation, I decided to stop using it to see if the FE want back down to 50. The next tank was 54.4 MPG and my current tank is over 56MPG at 400 miles. The average temps over all of the tanks mentioned was/is between 30-35F.

What I am sure of is that I have improved my driving technique even further. What I am not sure of is to what extent, if any the acetone had on FE. It was pretty much a waste of acetone because the test was not controlled. The two variables were Acetone and improved driving technique. IMO, there is no way not to introduce the improved driving technique bias into the test unless you make it impossible to do. And the only way to do that is to try, try ,try to improve FE until you "hit the wall". I am still not there yet, after years of trying and two years of extreme FE.

Do you have the self discipline not to try to improve FE during your testing? If so, you are much more disciplined than I am.:D

Hmm...I think you guys are missing a huge component of the experiment that I have designed. Not only do I not intend to stop increasing fuel economy through driving methods, I fully expect that fuel blends, driving conditions, and even my own vehicle will throw noise into the raw data. That is where the on/off cycling comes in.

Like I said in my original post, we're talking about doing 2-3 tanks on the additive followed 2-3 tanks off of the additive at least 2 or 3 times (4 or 5 would be better). From those trials you end up with two sets of data: one for driving with the additive and one for driving without it. This serves the very important purpose of testing both cases over similar conditions as circumstances change.

The truth is that you can't tell anything from that data just by looking at the straight mileage-time plot. (I guess it's possible but I really doubt it would be that easy.) You need to reduce it using any number of methods, none of which the average Joe Testimonial is likely to know about. But the point is that you can get meaningful results. It just takes some effort. :)

Like I said in my original post, we're talking about doing 2-3 tanks on the additive followed 2-3 tanks off of the additive at least 2 or 3 times (4 or 5 would be better). From those trials you end up with two sets of data: one for driving with the additive and one for driving without it.

I count four sets of data: one driving with the additive while continuously improving your technique, one driving without the additive while continuously improving your technique over and above the last 2-3 tanks, another one driving with the additive while continuously improving your technique over and above the last 4-6 tanks, and another one driving without the additive while continuously iimproving your technique over and above the last 6-8 tanks.

This serves the very important purpose of testing both cases over similar conditions as circumstances change.

But if you keep improving, your conditions are NOT similar. :D

I appreciate your effort to prove/disprove the effect of PIB. I'm just afraid that your results will be inconclusive if you don't wait for your FE to stabilize. Also, with a new car, things are still breaking in. FE will improve from that also.

But if you keep improving, your conditions are NOT similar. :D

Sure they are. Similar does not have to be identical for this to work. Trends in my driving, in conditions, vehicle, fuel, etc. would be evident in the fuel data without the additive. This is important for purposes of comparison. For example, lets assume that while I'm performing this experiment the average mean daily temperature increases with time (which it will or else I'm moving south.) If you want to know how that impacts FE for the fuel with additive (FWA) and neat fuel (NF) you can start by plotting FE vs. average temperature for each batch. If you get two curves that look exactly the same then you can't make any claim that FWA performs better than NF. To gauge the impact of my driving performance you do the same thing but just plot FE vs. Time and see what those two curves look like. Identical or close to it, it's hard to stay that there is any difference. Visible differences between the two and you are allowed to wonder.

I'll never claim that this is perfect, 'cause it isn't. But it is a pretty good way to keep from getting false positives. Improvements would have to be really significant (on the order of the manufacturer's 10-20% claim) for results to become visible. However this is something that one has to accept as an experimenter. Conditions in a real-world trial will never, ever be the same. Even stabilization of my own driving technique can't be confirmed with any degree of certainty. Worrying about inconclusive results because losing an insignificant result in the noise is, by definition, inconclusive. You can't prove a negative.

In short you do the best you can with what you have because if you do nothing then you guarantee zero knowledge gained. :)

Hi Brick:

___You own a 2002 Accord Coupe w/ a stick. Imho, she is worth a 45 - 46 lmpg, a 50 + tank, and a 65 + mpg segment. This is what raises the flags when someone starts speaking about increasing FE w/ additives or HW without knowing where there own personal peak really is. Because we are in the season of maximum temperature swings over a given week/month, I would rather see you perform your tests in late June/early July where in most locales, you have the least amount of temperature swing from high to low. By that time, I truly believe you will be punching out much better tanks once we get into the nitty gritty of optimizing your commute, using your terrain, handling your traffic, improving your setup, and removing any hint of personality from your driving habits. Dan makes a very good point about stabilizing your maximum and sustainable FE. Once the CleanMPG DBase is up and running, you will see graphs with the low to high swings over any given year and will notice an overall stabilization from early to mid-summer at some peak for most drivers. I think you will do the same and at that point, you will know how a 3 tank on/3 tank off additive solution actually helps or hinders. I look forward to your results but I would much rather see you punching out those sustainable 45 - 50 mpg tanks first and then go the additive route as there is less chance for an erroneous conclusion.

___Let me add something here. Before the Prius II - Marathon Attempt last August, I would have sworn up and down that hills no matter the shape and with a height delta > then one could maintain a DWL technique through would be a detriment to ones FE. Being an Insight driver who lived and died by Lean-Burn, I simply waved off any other possibility. Dan showed me otherwise in his Prius II on our first practice segment in Pittsburgh. To this day, I actually look forward to any height hills (not mountains just yet ;)) to increase my own FE in the Accord and Ranger with the techniques we use day in and day out. Some automobiles can take advantage of hills better then others of course and I would still take the Insight on the flats over any other. With slow speed hills and/or inner city driving, the Prius II or even an Escape HEV under EV would get the nod. I just wanted to pass along an experience that really changed the way I thought of other automobiles capabilities and created that many more opportunities no matter what I drive.

___I think as time moves on, you will find a similar improvement after you have explored and combined all the techniques available (opened up to all the possibilities). Once that has been achieved, your additive test(s) may yield a far more conclusive result. You are a relatively new hypermiler still improving by leaps and bounds and any test no matter how controlled will be skewed to a somewhat higher FE as time moves on.

___Good Luck

___Wayne

I gotta go with Brick on this- let him run his experiment and see what happens. It sure can't hurt, and it sound slike he understands the design of experiment pretty well. Worst case, he'll end up with an even cleaner engine from the extra detergent/solvent effect of the stuff.

(If you look at a lot of the magic potion 'data' its usually run with old, dirty engines. Hence, any solvent will make things better- acetone, ethanol, meth, MMT, PIB,...)

I do find it interesting that they mention its the equivilant of 150 octane like its supposed to mean something as far as FE is concerned.

I do find it interesting that they mention its the equivilant of 150 octane like its supposed to mean something as far as FE is concerned.


Yeah- agreed. They're harking back on old conceptions we learned from our Dads, which they learned from theirs. Back when high octane DID help most engines run better since timing was fixed, and the proper detonation was more likely to help FE, just like 3000mile oil changes WERE necessary.

BTW, just convinced my neighbor OUT of geting the tornado air swirly thingy. I'm embarrassed that I ever even thought it might help, way back in my unenlightened fuel-guzzling days.

The other inconsistency that I find is their claim that the additive will "stay in the system" for several tanks after you stop using it. That was a major red flag for me because the actual research I read claims that any impact it has on combustion is due to the effect on droplet formation. That 40 or 50ppm is supposedly holding the droplets together (for more uniform distribution) better than if the fuel were untreated. But they are claiming that you will keep on experiencing the results because it somehow coats and lubricates components in the fuel system and engine. What? So it's about droplet formation but it's about lubrication when you try to do an experiment like mine. Sounds like marketing and CYA tactics if you ask me.

Wayne, now I think I understand what your concern is. I guess the difference between your thinking and mine is that I am assuming that improvement to my driving will be gradual and progressive, whereas you seem to suggest that eventually I may just "get it" and start getting crazy FE numbers, thus throwing a wrench in the whole thing. (Please correct me if I am misunderstanding). If that's the case, I really hope you are right! Clearly there is much to be learned on my part. And in the end you may be right, and there may be too much noise in the data if I reach some kind of FE epiphany. But I can pretty much guarantee that it wouldn't cause any false positives if I am constantly pushing for FE. If I can push out a 45+MPG tank on the additive and it is me doing it, I should be able to do it again without the additive.

So, I don't know. It might make sense to take Wayne's advice and hold off for a few months. Maybe I should compromise and make a decision after two or three more tanks of straight fuel (if for no other reason than to get past the winter-blended fuel) to see what my FE numbers are doing. If it looks like I'm improving by leaps and bounds I will hold off a while longer.

I appreciate everyone's interest and and excellent criticism!