ATF as an Engine Oil substitute? Let's see what happens!

WIll automatic transmission fluid (ATF) work as a replacement for engine oil in the crankcase? Does ATF as good or better than engine oil? Does it “clean” sludge better than engine oil? Let’s find out! Thanks for supporting the channel:



31 thoughts on “ATF as an Engine Oil substitute? Let's see what happens!

  1. Hi Project Farm! Thanks for all the great videos; I really enjoy the topics and your approaches to create the test procedures and equipment! I had an idea for a new project video: Could you test ATF at different temperatures to examine their performance after being subjected to set periods of time at normal to extreme temperatures? I know I have seen quite a few charts from the transmission industry, that state the useful life of ATF, depending on the temperatures that the fluid is exposed to. For example, these charts will say if you can keep ATF temps below 175F, the fluid should be good for 100K miles. However, a temp of 220F (for how long?) will make your fluid only good for 50K miles or less. I know my Toyota Tacoma has a factory spec range of 122F to 176F, although I see temps higher than this (200F) during mountain road climbs (in my case, temp measured at torque converter outlet to cooling circuit (worst case/highest instantaneous readings)). I think at 300F, the "AT Oil Temp" light comes on, but I have never seen that! Anyhow, I take good care of my transmission (300K miles and 17 years on original unit), but I think a lot of your viewers would be interested in seeing an ATF video. Initial lubricity baseline, cold flow test, followed by exposure to several high temperature ranges, followed by lubricity checks against the baseline.

    Thanks again so much for the great content. Keep up the good work and I look forward to many more videos from the Project Farm!

  2. The detergent capabilities of ATF are very easily demonstrable and you've seen some evidence of it here, in fact in car engines it has been like wow! I also did it to one of my own vehicles years later after buying it used. The part that made me nervous is so much ending up in the oil so fast. The varnished OHC area instead of having varnish, had clean metal. I didn't run it long that way and made sure the oil was changed when it was good and hot. The guy at the dealership commented that it was very dirty and showed it to me but that was no surprise to me. (I do not do my oil changes myself anymore because for $8.00, recently raised to $15.00, the Honda dealer will change the oil if I bring my own oil and filter, and I don't have to dispose of the oil myself.)

    On lubricity, we used to put ATF in engines because it doubled the wear allowing more wear in less time for testing purposes. However, we were not involved in establishing that. We simply accepted as fact in Automotive Engineering. However, to their credit, they debunked a lot of theories such as by putting batteries on cement vs. a board for each class, and other things to root out wives tales or situations that occurred a very long time ago when there was different construction and the old tales were still hanging around.

    Another was detergent vs. non-detergent oil. The myth is detergent oils foam. That used to be the case when they first came out and before most people were born, but it was never the reason for the difference. Cars normally used flat head engines and splash lubrication with little dippers on the connecting rod bolts. In that case, the oil pan was a place for contaminants to settle and solidify. That was your oil filter. Every so often they would drop the easily accessible pan and clean it out. On small engines that aren't expected to have that type of lifespan, it is the same except you cannot drop the pan. With pressurized oil systems, you want to keep it in suspension so you can filter it out. Today, recommendations vary but often non-detergent is recommended and detergent oils OKed because of common availability and more frequent changes.

    Some recommendations for oil are based on what is normally available. For example, you may have a car with a recommend oil of 5W-20. That same engine today will have 0W-20 because it is now commonly available. You want the first number as low as possible and respect the second number. 0W-20 is not necessarily 5 less than 5W-20. It may be far less than that, which is desirable. Oil is ALWAYS too thick when the engine is cold and is when by far most of the wear occurs. The upper number is its ability to maintain its scuff resistance at normal and high temperatures. The reason on new cars that number can be lower has nothing to do with precision and everything to do with their roller valve train, which adds significant fuel efficiency, which is further enhanced by thinner oil, and reduces wear in many other parts of the engine as well as contributing to longevity. I do get comments at oil changes that it isn't what they recommend, but they have since noted it and don't ask me anymore.

    Another thing I learned from a friend who has owned tire stores his entire life is to go to the high side on tire pressures, and avoid large wheels which require larger tires. They wear better, ride better, are cheaper, and have much less rolling resistance. The 18" rims rims that came with it are in the top of the garage, and I have 16" rims that look just like them with the same offset and hub size. He was correct. I get great mileage, the tires last forever, and but the increased pressure makes it ride harder. Keep in mind that when you go around a corner, the inside of the tire and outside of the tire have to scrub the pavement, so you want the most pressure on the ground to be the middle because it is the only part that doesn't. Thus, I get better mileage and they wear evenly all the way across. I can tell at the pump every time when I have tires below my desired pressure.

  3. Ive used ATF as an engine flush a few times, i usually drain the engine oil, fill it back up with ATF and let it idle for 5-10 min then carry on with the oil change.

    I did it years ago on my 83 tercel, my friend said it stopped puffing blue after, i also did it on my brothers 97 tercel, got a lot of carbon chunks in the drained ATF and the filter after.

    It definitley helps but if the rings are really carboned up from lack of oil changes its not going to make a huge difference

  4. years ago (40) or so I would experience lifter noise , typical old ford thing, adding 1 qt of atf to the oil change would quiet them I never ran all atf . Haven’t ever experienced this in years , new oils seem to have cured this problem . I haven’t even thought about doing this for years, if the rattling not there , why would you .

  5. this test is useless, people are not running engines on pure ATF. they make is 5 to 1 ratio… 5 regular oil and 1 ATF. that way each oil does its stuff. this video is just stupid.

  6. Back when engine oil was crap and didn't include detergents,tricks like using ATF to prevent sludge was a good,with the high quality oils available,there is no need to be messing around with adding extra's to engine oil – if you buy a sludged up heap,then use old school methods like ATF to clean out sludge,but be aware that the thinned sludge moving through the engine can get into fine oil galleries and could block them..not good.

  7. I had a 68 Mustang 6 cyl 200 I had to put a new head gasket on. it had a water leak, and I ran it till it would not run no more . all the paint was gone. without letting it cool down. I put cold water in it . it sounded like a Chernobyl disaster and looked like one too! the lifters were dead stuck. I tried that, but they were dead Jim, dead. I had to try to tighten the rockers while the engine was running to get them to seat . it was the most abused car in the world, but sure learned a lot.

  8. Back in the day of Isuzu rodeos, I had a 97 Honda Passport with the v6 that made the loud lifter/rocker erm noise. I was advised to put a zero weight oil in and a quart of auto trans fluid, run it at least a couple hundred miles, then change it out. I will say, it actually DID quiet the noise down a large amount. Love the videos

  9. many years ago I picked up a 78¬†Camaro with a¬†305 in it¬†that had a bad lifer issue.¬† I had to remove the intake to clean the gunk away from the lifters and the drain back holes.¬† after doing this I did¬†a oil and trans mix to clean the engine out.¬† I did this 3 times in a row with amazing results.¬† the compression returned and the knock went away.¬† the engine had about 200.000 km on it.¬† I drove that car for 2 years without any issues and gave it to a friend who used the engine for a demolition car and won.¬† I would highly recommend this¬†treatment for¬†cleaning.¬† I have been taught to clean gently and slowly or the engine will fall apart inside.¬† What's¬† your¬†opinion?Your Show is awesome … thanks for taking the time to do¬†teaching us¬†what you know and learnGod Bless

  10. try some castor oil in the gas for cooling and more compression ? you need a lot of it to overcome carbon built up in a tweestroke i know and its about themp.. if you put enouf in it and youu keep the mixture rich there is no carbon …waht do you say about my vision ?

  11. I did some in depth research a couple years ago, and I found out that ATF is nothing more than 20-30wt hydraulic oil, and according to API, that's all that it's required to be.

  12. They say in ww2 on the eastern front, to keep engines from freezing up by gummed frozen oil, youd mix gas in the oil….when the engine heated up, it evaporated.

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