gas additive

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    What are folks doing regarding any fuel additives in their cars? I used to use something called CD2(or something like that) but it is no longer available. Does anyone have thoughts on the need for and additive and if so what is recommended?


    Syd: I suppose that there are as many recommendations as there are products. I started using Marvel Mystery Oil some 25 years ago adding four ounces to every ten gallons of gasoline. Later, a friend who was an outstanding mechanic sugggeted that two cycle engnie oil worked just as well as a fuel additive at a lower cost. That was about fifteen years ago. I have used two cycle engine oil at a rate of four ounces per ten gallons ever since. It has worked well in over 20,000 miles of driving mostly in the Series 33. Some two cycle oils tend to smoke a bit. Valnoline does not so that is what I use. The scale on the side of the quart bottles is very helpful in measuring the amount to be added.


    One of our problems in 10%-ethanol states is the longevity of the gasoline over winter. There is a new product called “StarTron” which claims to be enzyme-based and superior to Sta-Bil, which has been on the market for awhile. I bought some StarTron and dosed all the vintage iron with it in November, as well as the can of gas I use for the leaf blower. At this time, I can’t report on how well it compares to Sta-Bil, one way or the other. My experience with Sta-Bil is that it seems to lose effectiveness after four months.

    StarTron is pricier than Sta-Bil, but I found the best price at West Marine. Just be sure to get the StarTron product for gasoline engines rather than for diesels.

    I use Marvel Mystery Oil (MMO)– at the dosage Paul recommends — with success. Before using it, I’d been getting a sticky valve on one or the other of the two Series 80s about once a year. Strictly from a theoretical standpoint (I offer no science here), I use it rather than 2-cycle oil because MMO is naphtha-based and thus reportedly fosters the breakdown of hard carbon combustion chamber deposits into soft carbon which then sloughs off and is blown out the exhaust system. MMO was developed in the 1920s to address the problem of the poor-quality gasoline available at the time necessitated that cylinder heads had to be removed and “de-carbonized” every 15,000 miles or so. You pays yer money and you takes yer choice :-)



    George: Stabil makes two products, a blue liquid for marine use that is suppose to be better than the red stuff. I put this in the cars up north, because the prior spring I could not start the 31. It had been stored with the red stabil. (Eddie Minni came over from Mass. and got it going for me). Is the StarTron the blue stuff that I bought?


    Tony, I used the BLUE Startron but have used the RED Sta-Bil in the past (I hadn’t looked in marine stores for a marine version of Sta-Bil). I deliberately chose the marine product this time because of its touted superiority for long periods of vehicle disuse that is common to both marine engines and our vintage cars–except for you guys in Florida!

    Let me add to my MMO content that our L-head and T-head engines are not particularly efficient and thus arguably have a greater tendency to acquire carbon deposits in the cylinder heads than OHV engines.


    There is an article in the Feb. 2011 issue of Skinned Knuckles magazine (714-963-1558) about the problems of phase separation of gasoline/ethanol. This is another problem we face with the old cars and a very serious one. Suggest you read it.


    From my reading of the SK article that Gene mentioned, it is an explanation of why ethanol-laced gasoline “goes bad” over a few months: the ethanol (alcohol) actually separates from the gasoline. Further, alcohols absorb water from the atmosphere but reach a saturation point, aggravated for us because our fuel systems are vented to the atmosphere.

    My interpretation of the article is that we need to consider using a product like Sta-Bil or Startron especially during off-seasons.

    We have a reciprocity arrangement with SK. Perhaps Arnold Romberg, our PASB editor, can obtain permission to reprint the SK article in a future PASB.


    Are most of you still sticking with Stabil for an additive? In Pennsylvania – it was recommended to me to add blue marine Stabil – Any thoughts?


    Blue Stabil lasts longer. Use premium fuel as it also lasts longer. If you want gasoline without alcohol, do a on-line search on “Pure Gas”” and select the appropriate state.”


    Philomena, thanks for refreshing this old thread.

    Let me update by saying that I’ve had excellent success with (blue) Startron as found at marine stores, and need to replenish my supply. A little goes a long way: an initial dose is one ounce per 8 gallons of gas, with follow-on dose of one ounce per 16 gallons, but a pint of the product costs about $25.

    Again, I’ve had no experience with blue (marine) Sta-Bil, only with the red Sta-Bil as found at Home Depot for use in lawnmowers and other small gasoline engines–which I found generally unsatisfactory for automobile gasoline stabilization over the winter.


    Most marine engine manufacturers requite ethanol-free fuel, so try your local [if any] marinas for ethanol free fuel.

    Another option is to go to your local small airport and purchase aviation gasoline. It is close to being a synthetic gasoline. The reason being is that an airplane may sit for months without use, it has open tank vents to atmosphere, and the fuel MUST be good, or you risk engine failure or poor performance from the engine, And there is no ‘shoulder of the road’ up there to pull over and sort out any engine issues !!

    Not all airports will sell to car owners, one, the fuel has lead, and the fuel does not have road taxes added, So many places will not risk the potential issues from selling AvGas to a car collector. But it is the BEST fuel available for storing your car for the long winter.

    One of our PAS members used to work for ONAN corporation, which makes generators. The company did a test of several pump-grade gasolines and found that Amoco, Standard Oil, had the best fuel, It was the Premium fuel, it had the longest tank life, and the least varnish and other unstable contaminants.

    I do my best to buy Aviation fuel, but like this year, I’m not yet to the point of putting my cars away for the winter, even though there is snow on the ground.. It’s on ‘The LIST’ but I haven’t got down to that line yet..

    Greg Long


    My son did put ethanol-free fuel in last week, but there were about 2 gallons of ethanol gas in there prior to him doing that. I cannot get the Pierce started – as mentioned in another topic the starter is failing (will be removed – winter project). I will try to find Startron in my area. I know I can find the blue Stabil as an alternative.

    I have eight automobiles to be concerned with – this is such a nasty situation with the gas any more :(


    The ethanol free gasoline should be easier to get a stubborn engine running on. The ethanol in gasoline does not burn well or ignite well in our low compression engines.

    Had the existing ethanol-tainted gasoline been in the tank a long time? If so, it may have absorbed enough humidity or condensation inside the tank to have the ethanol be saturated, resulting in the fuel separating into water, saturated alcohol, and gasoline.

    So the water would be on the bottom of the tank, and be drawn in and be in the fuel pump and carburetor float bowl.

    Drain the carburetor [remove a main jet and let drain] catch what you drain out, and put in a clear glass jar, let it sit and see if it is homogenous, or stratified into layers.

    Will the engine fire on starting fluid ? It won’t run long, but should fire. Often ‘bad gas’ causing a no-start situation is not the gas, but an ignition problem.

    Hope this helps.

    Greg Long


    To me, the first issue is to get the starter operating correctly. If you have not already done so, clean ALL battery connections, both hot leads and grounds, especially the latter. By that, I mean both the connections to the battery but also those to the starter and to the battery ground. No sense risking burning up the starter. If cleaning those connections still results in “smoke,” remove starter and repair it before proceeding with trying to start the car.

    There is another potential problem area for a car which has not be started in a few months: The ignition point surfaces can acquire a coating from disuse, and this coating (oxidation) may prevent sufficient spark. Remove the distributor cap, and draw and **uncoated** business card between closed points to clean them. A very small shot of circuit cleaner or brake cleaner (non-flammable) may help, but it is the friction of the uncoated business card between each set of points held closed by the spring that really does the job. With dual points, begin with the closed set then crank the engine until the other set of points is closed and repeat for the second set.

    If the starter is operating properly, see if the plug wires produce a fat blue spark at least 1/4-inch long between plug wire end and plug during cranking with starter (a two-person job). Be sure to use insulated pliers to hold each wire the proper distance away from the plug. If you don’t have the fat blue spark, the ignition system needs to be corrected first.

    Hope this helps!


    Ok – exactly when are you guys arriving at my house to do all this? LOL

    Thank you for all your responses.


    Greg will be on his way as soon as the snow clears out of Michigan!

    He is our resident mechanical brain surgeon.


    Nice of you to volunteer Greg to check on the Pierce! LOL No snow here yet in Pennsylvania – fine by me!!!


    Peter, just send my your credit Card numbers, then I’ll give Philomena a call to set up the service call, on YOUR dime.

    Greg Long.


    It is amazing how these discussions resurrect themselves. I have recently bought Seafoam. Seems to work well, anyone else have any experience with Seafoam?


    It is also funny how this started as a discussion of gas additives and went to starter motors and then to my paying Greg’s travel to fix Philomela’s car.

    HA, HA, HA, HA!

    You just have to love the P-A guys & gals.

    I will refrain from commenting in the future, yeah, right!

    Oh yes, I use Seafoam and have for years for Winter Storage of marine engines.

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