Can I go back to regular oil after using full synthetic?

Discussion in 'Fox 5.0 Mustang Tech' started by 5.0 Nostalgia, Jun 22, 2004.

  1. I have been using Mobil 1 synthetic in my 89. The reason for using this is because the previous owner told me that was all he used. I have heard that once you start using a full synthetic you can't go back. Is this true? I want to change back because I don't drive the car much but always change the oil after 3 months. The big money spent on the Mobil 1 seems unnecessary. My car has 99k on it and I have heard that it is better to use regular oil because the synthetic can cause problems with particles breaking loose from seals.
  2. no keep the synthetic,regular oil breaks down worse than synthetic and leave thicker deposits/sludge ooh and what kinda snthetic do you change after 3 months i use amsoil and change it every 7,500 or 6 months. but unless you have a bad oil leak dont switch back because you engine has got use to the thinner oil and you have more parts being covered now.and the only time you should get deposits out of the block would be when you flush out your block with a engine flush machine due to the hot oil/chemicals being flushed in.
  3. Great question. I'd like to know too.
  4. depending upon how long you have been running the PAO in there, you may have cleaned the seals already (synthetic has lots of detergents).

    you can go back to dino. no biggie. or you could leave the M1 in for 6 months or so. on a bike or two of mine that dont get ridden much, i change the oil once a year (M1). pretty common practice.
  5. I use it in my BMW. I change it every 10k or 4 months....whichever comes sooner. A little less in the Mustangs. Why go back to regular oil anyway? The cost of using synthetic is the is almost the same and it works a lot better.
  6. lol royal purple owns!
  7. QDRHRSE, you drive a lot (4 mo or 10K would be like 30K miles a year if you get close to 10K in the 4 months). :)
  8. Of course you can go back. I've been turning wrenches for years and have never scene problems with this.
  9. Totally safe to go back.
  10. Just a myth is all it is. You could use a different name brand, and a different type of oil in your engine every oil change and it woudn't matter. Synthetic is definetly the way to go. Not that Conventional is bad or anything..... But Synthetic is great as it's reduces friction, cleaner engine, less break down etc. etc. etc. etc. The money you pay for synthetic is worth it in the long run.

  11. ya know on the amsoil all u do is change the filter in 6 moths and a full change in 12 months. but thats only if u follow the directions. but changing the oil early can't hurt.

  12. this is true, however many dont like to do it. your oil will still have contaminates in it - blowby, hydrocarbons, etc.

    if i were to leave oil in for that long, i would do a UOA periodically to check on things.....i have not read Amsoil's [extended] OCI recommendation info - they might even recommend a UOA.
  13. Thanks for the help. I guess I will stay with synthetic because the car has been running on it for at least 2 years. It just seems like the car burns more of it than regular oil. None of my other Mustangs use as much oil and they all have regular oil. I guess it is just a coincidence.
  14. I have heard that you can't go back, but it's good to know that the seniors have lead us in the right direction. If you have been using synthetic oil, what oil could you go back to?
  15. like i siad above if you have a oil leak or burn oil synthetic will make it worse. i reccomend going to a high milage oil because it is a thick oil and will prevent oil loss and consumption. and i dont know who said you can change brands and stuff every change????? every oil has different additives in it and is designed to work best for your set up so let that guy do that and see how long it lasts.(at my work we sell oil that is cheap as balls and has no additives and is only recycled oil)
  16. 1. regular oil tends to act like a scab in the leaks and the 'build up' is what helps keep the oil in the engine.

    2. the synthetics tend to have cleaners in them and run thinner and doesn't coagulate and can infact clear the already colagualted traditional oil. thats how come it will burn more oil than traditional.

    not all engines are recomended to run synthetic especially if its a high mile engine.

  17. Exactly. You can mix brands weights go back to regular oil etc. The only thing is if you go from regular oil to synthetic oil and your engine has 100K or so on it it has a tendency to slide past the rings because the lubricity is so much greater. Also a common misconception about synthetic oil is that it's synthetic even tho it's really not. When they manufacture oil they take a big barrel of crued oil and subject it to heat. At the bottom of the barrel you get thick asphalt like material. Then you get heavy oils. Then light oils. Then gasoline. Then diesel. Then butaine, octaine etc etc etc. To make each barrel more profitable they mix heavy oils with some light oils and get oil. Synthetic is just the pure light oils (nothing actually synthetic about it). Also you change oil to get rid of the CONTAMINATES not because the oil (usally) dosen't break down therefore you SHOULD change synthetic oils as often as standard oils. IMHO for most street cars synth. oils are a waste of money.
  18. i think you are talking about cracked base stock (like group III's). they are called syntetic, but are highly refined dino oil.
    there are PAO basestock's, (mobil 1, etc).....which are not dino derived, as i understand it.
  19. Yup, you can switch back. But since you don't drive it much, I'd just extend the oil change interval on the Mobil 1. I have many friends that average 8-12K a year on their cars, and they just change the oil once a year; they put a filter in it and top it up every 3 months. That ought to work just fine for you.
  20. what about the blended stuff? i've used that as its half and half, but cheaper than full synthetic.