me and my friend were talking about synthetic oil and he said that once u put synthetic oil in your car you cant go back to regular oil because it will damage your engine is this true?

 

Nope, you can switch back if you want. - As long as you put the proper weight in, it will have no adverse effects on your engine.

 

just make sure not to mix. Either one or the other.

 

You can safely mix both synthetic and non synthetic oils! Why do you think they make durablend? The difference between the 2 is the way the molecules are made, non synthetic has jagged edged molecules to where the synthetic has perfectly round molecules. This returns lower friction and wear on the engine! As far as not being able to go back to regular? Thats a myth!!! You can go back anytime!

 

what you shouldn't do is go from regular to synthetic on motors that are old or have a lot of mile on them.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Dr.c &raquo;</TD></TR><TR><TD CLASS="quote">You can safely mix both synthetic and non synthetic oils! Why do you think they make durablend? </TD></TR></TABLE>

That's one company making a special blend that they know is compatible. When 2 different companies are using different formulas and additives the result of mixing is unknown. I'm not saying your engine is going to blow up, you're just going to end up with something that may not work as well. Why mix when you don't have to (usually). But yes you can go back and forth.

From a board dedicated to oils: http://theoildrop.server101.com/ubb/ultimatebb.php

"There is no hard data to prove that two oils of the same performance level mixed together will still perform as well as they do individually. The oil industry only runs a few lab tests to make sure additives are compatible when different brands are mixed, but do not conduct engine tests or mixed brand tests. We do know that different oil brands can lay down deposits in different areas of an engine, and there's always the possibility that if you mix two brands, you may get the worst of both worlds, instead of the best. All this applies to mixing oils in engines. Changing your brand of engine oil altogether is no problem. However, you should flush the existing oil before adding the new oil. You should also be aware that engines typically go through a period of adjustment when making the transition from one oil to another. Because brands are formulated with different additives, a new brand may act differently than the old one at first. Increased oil consumption and leaking seals are common adjustment problems. Since additives contain metals, those metals may show up in your first oil analysis reports with the new oil."

different oil companies don't even recommend using different oil brands, e.g.,
http://www.chevron.com/prodser....shtm

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by murtnabila &raquo;</TD></TR><TR><TD CLASS="quote">what you shouldn't do is go from regular to synthetic on motors that are old or have a lot of mile on them.</TD></TR></TABLE>

Why not? Please enlighten me.

so my 91DA w/ 153, 037mi fits your description?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by chitwn91rs &raquo;</TD></TR><TR><TD CLASS="quote">

Why not? Please enlighten me.

so my 91DA w/ 153, 037mi fits your description?</TD></TR></TABLE>

Depends on how it was mantained. There is a small chance that if your motor is all sludged up that the synthetic will remove the deposits and possibly cause a gasket leak.

These synthetic / non-synthetic rumors and heresay are mostly due to the fact that when syn started to get popular, some older cars had problems with leaks and things because the motors and gaskets were not designed to work with synthetics, and it caused problems. Modern motors are designed to work with both, so there should be no problems.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by EX_AutoXer &raquo;</TD></TR><TR><TD CLASS="quote">These synthetic / non-synthetic rumors and heresay are mostly due to the fact that when syn started to get popular, some older cars had problems with leaks and things because the motors and gaskets were not designed to work with synthetics, and it caused problems. Modern motors are designed to work with both, so there should be no problems.</TD></TR></TABLE>

Alot of these synth rumors also got started because there were few or no standards at the time (1) for compatibility between synthetic lubricants and internal engine parts such as seals, and (2) for compatibility between conventional and synthetic lubricants. It is amazing that such rumors persist 30 years after the fact.

And as for mixing the two, I personally would not mix significant amounts of one with significant amonts of the other. The small amount of old oil that remains after an oil change is not going to hurt things. But I would not add a quart of synth to an engine with conventional that is a quart low (or vice versa).

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Dr.c &raquo;</TD></TR><TR><TD CLASS="quote">non synthetic has jagged edged molecules to where the synthetic has perfectly round molecules. This returns lower friction and wear on the engine!</TD></TR></TABLE>

Yeah, you don't want those nasty jagged oil molecules wearing out your engine...

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by chitwn91rs &raquo;</TD></TR><TR><TD CLASS="quote">

Why not? Please enlighten me.

so my 91DA w/ 153, 037mi fits your description?</TD></TR></TABLE>

Main reason is oil leaks as stated. What happens is conventional oil will slowly start to sludge up and when you start using synthetic it starts to clean the sludge away. When it does the seals that have been bad, but not leaking, start to leak. The sludged oil that was acting like a sealant is no longer there and the syn. oil is leaking out. This usually only applies to poorly maintained motors or high mileage/old motors.

 

personally, stick with one type. switching up constantly cannot be good. Besides, its easier and more consistant if you stick to one type. personally i use mobil 1 full synthetic

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by bluemax189 &raquo;</TD></TR><TR><TD CLASS="quote"> switching up constantly cannot be good. </TD></TR></TABLE>

Do you have any basis for this statement? When I first got my car, it was tough getting full synthetic in 5W-20 or 30, it wasn't that common yet. Sometimes I would have to go with a blend, or even full dino oil if I couldn't find the synthetic. I have had zero problems, and no abnormal wear or leaks on my engine at all.

On a side note, Castrol used to have a question in the FAQ section about mixing synthetic and conventional. It said that it was okay to do (if they're the same weights), but their syn blend would provide better protection than mixing the two yourself because the blend was specifically engineered to get the best properties of the oils.