Okay I found out the guy who I bought my 86 from used synthetic oil in it the last time he changed the oil. I would like to swith back to regular oil because of the info you have all shared with me is this possible?

Just do your next oil change with regular oil.

Then why is it that you hear people say that once you go synthetic you can not switch back?

I have no idea why they say that, but you should be fine.

One thing is for sure, it's better to switch back now than never switch back. It's probably the same thing like people say about switching from a oil brand to another, just rumors that's all. :director:

Thanks for the info what oil do you guys suggest that will burn cleanly?

I use Chevron 20w 50.

I used castrol GTX for a long time. I still use it in the other RX-7's, but I use Mobil 1 in my car.

if i were you i would stay with synthetic because when the motor gets hot the oil gets thicker there for your allways going to have lubrication when you need it. such as, track racing or long halls or whatever. its just better.

But a small amount of oil is injected into the air/fuel mixture and burned during combustion. Most synthetic oils will leave carbon deposits when they are burned. And that is not a good thing with rotaries.