Changing oil types ....

[Metricman]

I have read on this forum here and there that once you change to synthetic oil you can not go back to a standard petrolleum based oil ? Is that true and if so why not ?
Thanks, Mike

[mountainmotor]

You can switch back and forth every oil change if you want but thats not the way to get full benefits from synthetic when diluting the new incoming synlube with residual mineral oil .

Go to the Mobil website and read the FAQ's on this subject for more information .

[coop427]

(Metricman @ Sep. 29 2006,11:39) I have read on this forum here and there that once you change to synthetic oil you can not go back to a standard petrolleum based oil ?  Is that true and if so why not ?  
Thanks, Mike

No not true at all. You can use either one doesn't matter, you can mix them if you had to.

[NightCrawler]

Anyone who tells you that believes this. Some synthetic residue will stay on the engine parts after the enigne is drained. Once you put the regular oil in it will slide off of the synthetic oil that was left in the engine, prohibiting the regular oil from doing its job properly.

I was told the "once synthetic always synthetic" thing a few years back. When I asked why, that was the explanation I was given.

[coop427]

(Spigga @ Oct. 09 2006,12:51) Anyone who tells you that believes this. Some synthetic residue will stay on the engine parts after the enigne is drained. Once you put the regular oil in it will slide off of the synthetic oil that was left in the engine, prohibiting the regular oil from doing its job properly.

I was told the "once synthetic always synthetic" thing a few years back. When I asked why, that was the explanation I was given.

That makes a lot of sense.

That sounds like a explanation from a

[Ride_or_Fish]

(Spigga @ Oct. 09 2006,12:51) Anyone who tells you that believes this. Some synthetic residue will stay on the engine parts after the enigne is drained. Once you put the regular oil in it will slide off of the synthetic oil that was left in the engine, prohibiting the regular oil from doing its job properly.

I was told the "once synthetic always synthetic" thing a few years back. When I asked why, that was the explanation I was given.

That sounds like the bean oils from decades ago that was most commonly used in dirt bikes. I think the oil industry is way beyond that technology today.

[VelvetJones]

I have 107,000 miles on my truck and I use a different brand/weight/syn and non syn every stinking time.

I do this just to show that it doesnt matter. I have used even the cheap 10w-30. I use synthetic and conventional. Havoline, castrol, mobil and every brand you can think of. I have had 0 problems the engine runs exactly like it always has. I can keep doing it forever with 0 problems.

Oil is oil is oil. Syn has higher heat handling and no wax to build up like conventional oil. I have read a million different things and seen the motor oil bible and I agree that overall synthetic is a better oil. However using conventional oil will not hurt you a bit. Synthetic oil is not going to add 100,000 miles to an engine. If you have problems at 200,000 miles on conventional oil you would have had the same problem at the same mileage with synthetic. EDIT Thats taking into account you did regular fluid and filter changes.

-vJ-

[ozz]

I just used dino oil in the busa this oil change had syn in it before that it aint gonna hurt it