ATF in gasoline?

I have an old (1977) MB where I mix ATF about 1% in the gasoline. It keeps the fuel line and top end clean -- valves, injectors, etc. Has anybody ever tried this in a current Porsche? The engines are much more technically advanced than engines from 34 years ago, so I wouldn't expect much. It might even cause problems. Nevertheless, I thought I would ask.

New to me.

Sounds like an old wive's tale to me...

rbpeirce, so you really added ATF to your MG's fuel and saw a real difference? ATF is 85-90% base oil and 10-15% additives to modify the viscosity and reduce wear. How did the plugs look? I'm curious if you experienced greater fouling inside the combustion chamber. It's the additive package I would be concerned about, since it's probably not designed to be clean burning! But on your original question, I've never tried this and definitely would not. Between regular (every 3K (conventional oil) to 5K (synthetic oil) oil changes and avoiding discount gas stations, I haven't experienced any issues due to fuel fouling or valve train deposits in any of our vehicles over the years. I don't see the need to use any fuel or oil additives, just buy quality products to start with. In fact, I just replaced the fuel lines on my 97 Dodge Ram 4X4 because they were corroding from the outside. The inside of the lines were clean. This old beast has 128K miles, including about 60K burning ethanol blends. It sits outside all the time, starts great and runs great. Of course, the front U-joints fail every 50K miles, the intake manifold gasket went at 70k miles, the rear pinion seal at 75 and the outside mirrors started to fall off at 80K miles. The paint is starting to flake on the roof and I touch up body scratches with black gloss Rustoleum (flat black if I run out of gloss...) But I can't complain, the fuel system is clean!

Anyone here ever use Marvel Mystery Oil ? ::Marvel Mystery Oil::

Read the Goldwing motorcycle forums. You'll find hundreds of majical mixtures for fuel and oil which supposedly work miracles......from Sea Foam to Amsoil to whatever. I share the experience of never using any of them, and never having had a problem on any of my vehicles (knock on wood).

MG: I agree with all you said except avoiding discount gas stations. Here's why: every tank truck that is loaded at every terminal has a USEPA required additive injected into the gasoline; it doesn't matter what station it is going to. There are only 2 or 3 additive manufacturers left, Chevron , Shell, and Lubrizol at last check. The difference between the additive that goes into BP or Chevron gas versus what goes into an independent's gas would require a research chemist to make the distinction, it's nil. The additive injection requirements are so stringent that we used to charge $0.0025 per gallon just for the record keeping, that didn't include the additive itself. The only issue I would have with an independent would be if they were only selling 5,000 gallons per month at their bait shop, where they might be having some water issues due to lack of turnover, but for the most part the Quik Trips, Sheetz' and Racetracs of the world are turning their tanks nearly once a day, and pulling from the same racks as ExxonMobil, Shell, etc.

I've heard of mixing ATF in fuel, but only in older cars, like your 1977 MB. I've also heard of pouring it (SLOWLY) down the carb while the engine is running, or letting it slowly get sucked into a vacuum line. This can really clean your combustion chambers, but you need to be really careful about hydrolock. I think one of the reasons it was used in the past was because 1) there were no good alternatives and 2) older cars need more of this type of cleaning than newer cars. I certainly wouldn't use it now, and certainly not on your modern Porsche. On the other hand, adding a bottle of Techron or Gumout Regane to the tank now and then won't hurt anything. I think some cheap gas stations don't put much of these cleaners in, or they use the weaker ones, barely meeting the minimum requirements or even not meeting them (to save money). Porsche even recommends Techron . To be sure, some cars need it more than others. I've had a couple of cars that really responded well to these cleaners, while on others, it seems to make no difference at all. If you car really has a problem with gummed up combustion chambers, a product like SeaFoam , or even distilled water, would be a better choice than ATF. But I seriously doubt your modern Porsche needs this. I did it on my 993, but I think my combustion chambers were pretty carbon fouled. It made a big difference.

The "Good old boys" in the south would pour a quart of ATF down the carb [remember them?] to clean the valves. Or some other dumb reason. You did this while the engine was running. Not a chance I'd use ATF for other than it's intended pupose today.

I resemble that remark....grew up in NC. Saw my Dad do that with our 1954 Ford (what a sweet ride....wish I still had it, fender skirts and curb finders and all). Smoked like crazy for about 5 minutes. Did the little 239CI V8 run any better? With a two-speed Fordamatic transmission, who could tell?:hilarious:

Sure wouldn't help the catalytic converters much and they ain't cheap

I've been running it for several years in my 1977 MB as have many others in their old MBs. No problems to report. OTOH, I am told modern engines are not as prone to carbon build-up so ATF isn't necessary.

Benefits of doing this questionable. Fuel is a solvent and will work to keep the fuel lines and top end clean. Modern gasoline has a tiny bit (IIRC around 0.5%) of oil added anyway to provides some lubrication to the injectors and some resistance to corrosion for any ferrous metals in the fuel system. Just buy name brand gas of the proper octane rating from a busy station and leave the ATF in the AT. Sincerely, Rockster.