ok im confused ...again.
some guys have told me that the good part of synthetics is, you can use conventional oil again even if you used full synthetic .
but some say to never ever do that because i can mess up the engine or something else
so im wondering if there is a website where they are specific about doing it or not
so far i visited almost any oil website and i cant find anything
thanks again

 

Synthetic should be used after the break in period.

 

and after going with sythectics DONT switch back is how I have always heard it

 

What about the other way round?

 

It really dosent matter. You should stay with one type of oil, down to a certan brand and move between weights not specs for the best performance. Different oil's have different chemical additives making them act differently and by mixing them they react to temp and break down differently... sometimes not in a positive way. I guess the major problem with constantly switching oil is that you cant compleatly flush a system without going though great lengths to do so.... long story short- stay with on brand, one style of oil, and change weights in sequence with seasons and you will be fine. My dads car is pusing 300,000 miles and its got quaker state high millage oil since 80k and it dosent leek/burn a drop of oil.

 

Not when your running it in....

 

All mercadies come from the factory full of mobil 1 super syntech. Yes a conventional oil helps bed the rings into the walls but its not nessciary.

 

i strongly dissagree. I have read in many places that using "petrolium run-in oil" is by far the best thing to do and it makes perfect sence. Also some engine companies are changing their run in manuals from "take it easy" to a much more agressive method that has been proven to be MUCH more effective. For example here is something...

http://www.mototuneusa.com/break_in_secrets.htm

 

I have rebuild/broken in my fair share of motors and I know what it takes to break in a motor so you dont have to go though that redrick with me...

If you disagree so strongly call up sadies and tell them they are equiping their cars with the wrong oil.

 

I was just backing up my point. It gives an explanation for what i said. The dude on that site challenged honda and got them to listen...