changing back&forth from convetional <--> syn oil

[cathy]

(from post #6
http://www.benzworld.org/forums/w140-s-class/1303785-synthetic-oil-vs-regular-oil.html)

Someone said "...switching back and fourth is not dangerous to the engine componts(there made out of metal and iron)but extremely dangerous to the gaskets and other rubber parts,as soon as those parts have synthetic oil on them and you switch back to normal oil then can dry out from the lack of petroleum that is in synthetic oil.so in other word either stick with Syn Oil or Normal Oil.never go back and fourth."

Do you think this is true? Synthetic still provides lubrication for gaskets, right?

 

[Kuato]

NO worries switching either way.

Some have noticed a little seepage when moving an older vehicle from "normal" or conventional oil to synthetic, which goes away if the seals are otherwise in good shape.

Synthetic lubricates seals very well.

 

[147_Grain]

Originally Posted By: cathy
Synthetic still provides lubrication for gaskets, right?




YES!

Synthetic oils and the research into them have resulted in excellent protection of seals and gaskets, which are also of higher quality than those of yesteryear.

 

[mongo161]

What about the folks that use Synthetic Blends?

Just read the saying underneath this post......lots of misinformation out there in the world today......

 

[KitaCam]

Originally Posted By: cathy
(from post #6
http://www.benzworld.org/forums/w140-s-class/1303785-synthetic-oil-vs-regular-oil.html)

Someone said "...switching back and fourth is not dangerous to the engine componts(there made out of metal and iron)but extremely dangerous to the gaskets and other rubber parts,as soon as those parts have synthetic oil on them and you switch back to normal oil then can dry out from the lack of petroleum that is in synthetic oil.so in other word either stick with Syn Oil or Normal Oil.never go back and fourth."

Do you think this is true? Synthetic still provides lubrication for gaskets, right?



This quote should become a sticky as a classic example of how unintelligent, and unintelligible, the internet can be...so much so obviously wrong here...the issue is not synthetic vs conventional, but the additives in each that serve specific purposes...as well as the fact that different engines (even of the same make/model) respond differently to the different chemical makeup found in different brands and oil "models"...

The one safe route for the most conservative/paranoid among us (me included) is to stick with the same brand (and weight range) when switching between different types of oil...whether different dinos, different blends, different syns...but going between syn and dino being "extremely dangerous" of course not...

 

[Voltmaster]

I wouldnt recomend it,

like the article said its the gaskets that are going to go bad not the moving parts.

Its ok if it happens but dont get in habbit, use all of one type , then switch. its ok to mix so if you have couple qt left of one type just put it in with rest.

 

[cathy]

this is for '94 mercedes car.

 

[Maxima97]

I do this all the time. In winter, use synthetic. Use dino in summer.

 

[SLCraig]

Originally Posted By: Maxima97
I do this all the time. In winter, use synthetic. Use dino in summer.


Same.
Just went from M1 to Pennzoil conventional last weekend.

 

[Astro14]

Cathy, for that vintage Mercedes, it's simpler to go with a 5W40 or a 0W40 rather than try and match all the viscosity/temperature recommendations in the OM.

Some good choices include Mobil 1 0W40 and Shell Rotella T6 5W40...other good oils exist but you can get those 2 easily at Walmart and they cover everything from summer to winter viscosity required in your OM.

 

[Garak]

Originally Posted By: Astro14
Cathy, for that vintage Mercedes, it's simpler to go with a 5W40 or a 0W40 rather than try and match all the viscosity/temperature recommendations in the OM.

Absolutely. In the day before the proprietary specs, they were all calling for things like 15w40 in the summer and 5w30 in the winter. A 5w-40 or 0w-40 year round fill is a little easier to handle, especially if one doesn't accumulate enough miles to make seasonal changes worth it.

 

[Zeus103363]

I have a 99 Honda Accord with 212k and I have swapped from conventional to synthetic and everywhere in-between over the years and the ole Honda hasn't missed a beat! Had one tiny oil leak at the valve cover gasket which was easily fixed and it wasn't the oils fault. Swap all you like. We all mite be surprised as to how similar conventional and synthetic really is!

 

[ufbbc]

It's nonsense. My truck was on dino only for 120,000mi. Went to Quaker State Ultimate Durability Full Synthetic 2800mi & a few months ago. No issues whatsoever. Now going to longer OCI's.

 

[ufbbc]

Update - I have had Quaker State Ultimate Durability in for about 3000 miles now (at 123,000mi)and still no leaks. But oil consumption is up. I have added a quart so far. I had never added oil with dino between changes for 120,000 miles. It may have started dropping a little as it aged, but nothing like this. Thoughts?

 

[Hethaerto]

Originally Posted By: ufbbc
Update - I have had Quaker State Ultimate Durability in for about 3000 miles now (at 123,000mi)and still no leaks. But oil consumption is up. I have added a quart so far. I had never added oil with dino between changes for 120,000 miles. It may have started dropping a little as it aged, but nothing like this. Thoughts?


The syn probably cleaned up your ring packs, they're probably a little worn, and the smaller syn molecules are slipping past your rings and into the cylinder and burning off.

Maybe go for a thicker oil?

 

[RF Overlord]

Originally Posted By: cathy
(from post #6
http://www.benzworld.org/forums/w140-s-class/1303785-synthetic-oil-vs-regular-oil.html)

"...but extremely dangerous to the gaskets and other rubber parts,as soon as those parts have synthetic oil on them and you switch back to normal oil then can dry out from the lack of petroleum that is in synthetic oil...so in other word either stick with Syn Oil or Normal Oil.never go back and fourth."

Do you think this is true?
No, it's a complete crock. WAY back when synthetics were first introduced, there were seal-compatibility issues. Those issues were solved fairly quickly. The info that nitwit is spewing is at least 30 years obsolete.

 

[ufbbc]

Actually I was wrong above. I am at 124,000 miles so it has been 4000 miles for that usage.

 

[gregoron]

My 2000 VW Jetta had 111k miles on it when I switched to synthetic from dino. No problems. I did it to extend my OCI. I have no fear going back to dino if ever.

 

[default]

I just dumped Mobil 1 15w50 into my Yugo, yes 1988 Yugo, the other day, its not leaking any faster/more places than it was.

Have 2k on a current oil change of Pennzoil Ultra in my 99 Prizm that likely saw nothing but cheap conventional 5w30 oil its whole life, didnt leak before, not leaking now. Nor burning much either.

 

[fdcg27]

Since most syns are really highly refined mineral oils (Grp III), I doubt that it would make any difference.
I don't think the gaskets would be able to tell the difference between hydrocracked Grp II basestock and hydrocracked some more Grp III basestock.
OTOH, gaskets and seals on older Benz and BMW engines were suspect to begin with, and I say this after four old Benzes and two old BMWs.