Synthetic oil dries out seals.

[AZjeff]

High Mileage versions of engine oils have extra seal restorative products in them that can actually restore a seal and stop it from leaking if it has just dried out from too much use of a synthetic engine oil. Some synthetic engine oils will dry out the RMS and start it leaking.

This quote came from a respected long time member on another automotive forum I frequent. No use trying to clarify since it would result in an ugly dog pile for insinuating the esteemed member wrong. Some myths just won't die.

 

[Lubener]

He's entilitled to his opinion. I fail to see any reason to post his quotation.

 

[bdcardinal]

I've learned that getting into oil discussions on other sites results in people with little to no knowledge or desire to learn dragging me down to their level and beating me with experience.

 

[JavierH19]

Not as bad as synthetic gear oil which apparently rusts them out.....

 

[RDY4WAR]

Such as that gets old. The same bad information just gets regurgitated over and over. Synthetic oil drying out seals and causing leaks is the big myth, but there's also the myth there of high mileage oil stopping a seal leak. The additional amount of ester-based seal conditioner in High Mileage oil is quite small. It's just enough to keep a seal pliable a little longer. It's not enough to reverse the condition of an already dry rotted seal, much less stop a leak. It may help a little bit, slow the leak a little bit, but highly unlikely to stop a leak or repair the seal completely.

I blame hyperbolic marketing for a lot of these myths.

 

[double vanos]

My seals are dry… so is the whole underside of the car!

 

[Jetronic]

And some synthetic oils make seals swell, soft and ultimately weaker. Mineral oils affect seals aswell btw

Maybe if you want to keep your seals tip top, the best course of action is no oil....

 

[AZjeff]

He's entilitled to his opinion. I fail to see any reason to post his quotation.

He doesn't present it as an opinion but as fact, no IMO present. People less versed in oil and what it does and doesn't do will believe his incorrect assertion. Can't recall anyone saying synthetic dries out seals before.

 

[wwillson]

Not as bad as synthetic gear oil which apparently rusts them out.....

From the outside, right?

 

[UncleDave]

With none in 30 years I'll take my chances going forward.

 

[BISCUT]

After 160k of synthetic only on my 17 Outback, my seals must be dry by now! Is anyone able to recommend the right oil for me?

 

[Sayjac]

No use trying to clarify since it would result in an ugly dog pile for insinuating the esteemed member wrong.

Sooo, an esteemed member with a steaming pile?

Esteemed member should have stopped after the words, "dried out."

 

[SuperSalad]

I've learned that getting into oil discussions on other sites results in people with little to no knowledge or desire to learn dragging me down to their level and beating me with experience.

You go to other sites for that?

 

[bullwinkle]

Since when do seals “dry out”? Does the guy mean “harden”? I’m always very suspicious of people who can’t even phrase statements properly.

 

[Soft Cars]

He's entilitled to his opinion. I fail to see any reason to post his quotation.

That's called dragging mud in from other forums.

 

[We're Metals]

What is a synthetic oil?

 

[earlyre]

we have a nationally ranked/known Auto/Diesel/Motorsports college here in town... one of the instructors, who the local TV station and Newspapers have on call as an "Auto Expert" is still teaching young mechanics that not only can't you mix Conventional/Synthetic oil, but that if you put synthetic in, you can never put Conventional in it again...

few years back i was working retail with one of the students, who blew up the 5.3 in his Silverado, he got mad at the Chevy dealer back in his hometown for putting synthetic oil in his new engine..."cuz now I can't use regular oil any more!"

never mind that ( now i could be wrong, but i'm fairly certain...) chevy specs synthetic oil... and he had it done at the Chevy Dealer...

 

[billt460]

So.... Synthetic oil "hardens" seals? If I drop a lump of coal in it will I have a diamond in 6 months?

 

[ATex7239]

You should just post a picture of every major brand’s full synthetic high mileage oil with the caption “Welp, this is awkward…”

 

[bdcardinal]

You go to other sites for that?

No, no, God no. I only go to one other car forum now, and on there when people ask questions they get referred here. But sometimes I unknowingly stumble into the minefield of oil lack of knowledge and have to quickly scramble out.