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Re: switching to synthetic at 100k

"Josh" wrote;

Not many years ago, I was told to beware switching between regular and >synthetic oils because, if you switched to synthetic you couldn't switch >back to regular ever again.

You're absolutely correct Josh, that was a bunch of crap. Switch back if you have to, but I don't know why anyone would?

I was told that the oils didn't "mix" and would >ruin my engine. What a load of nonsense.

True again! The oils can be mixed. Example, look at the "blended" oils for sale on the market today (which is a gimick, don't buy them).

But the above illustrates the point >that there is a lot of misinformation out there on synthetic oils. >There is no evidence that synthetic oil provides any better protection than >conventional oil.

Well, Josh, here we have a problem. Good synthetic oils basically stop metal to metal wear almost completely if everything is machined and fitted correctly. This is a proven fact, not lore, not rubbish nor misinformation. There is plenty of evidence and much thorough testing has been done and I have been involved in some of it. I am retired so I have nothing to gain from lying to you.

It does provide a good deal of piece-of-mind, though. That >could be more important than the extra $$ saved continuing to use >conventional oil. >josh

I agree with you here Josh, peace of mind is the most important factor. A car can be replaced, but time and energy spent worrying about things is lost forever.

"The Ole Factory Rep"

Reply to
<tech-rep
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I have a 00 2.5RS with 94k miles on it and I had the same dilemma recently.

Modern synthetic oils are definitely superior to dino oils.

However...

The main problem with switching from dino to synthetic oil at such high mileage is not that the oils aren't compatible, it's that years of dino oil builds up 'gunk seals' around the seals in your engine. When you put in synthetic oil, it will wash all of those out and possibly cause oil leaks.

I know people will say that those seals probably needed to be replaced anyway, but hey... they weren't leaking or causing me any problems before I switched to synthetic, and I don't think it matters whether it's rubber or 'gunk' keeping the oil from leaking... the seals are 'sealing', therefore they're good!

For that reason alone I stuck with dino.

Reply to
Dmitriy

That gunk that gets released can also collect on the oil pump pickup screen and cause reduced oil pressure, or block it completely. I recall Hot Rod magazine went to overhaul a '69 Chevelle with 150K and for that purpose they switched over to synth to clean everything out prior to the rebuild. Don't ask me why, I didn't write, just read it. Maybe someone here can answer why they'd do that to the motor when the plan was a rebuild anyway.

-- John

Reply to
John

Hi,

Two possibilities:

a) It's Hot Rod magazine. While they have SOME pretty good info most of the time, I've seen stuff over the years that definitely came from "them good ol' boys what's lost most of their teeth." So who knows what THAT crowd might have been thinking!

b) It's Hot Rod magazine. Since they have SOME pretty good info most of the time, maybe one of their brighter bulbs wanted to see a "worst case" test. A '69 w/ 150k miles (was that the original engine?) has probably seen all kinds of "abuse" (albeit some unintentional, just time related!), so they might have been looking to prove or disprove some of the "common knowledge" about synthetics, and the impending teardown would give them a quick, firsthand look?

I'm sure there are a host of other possibilities!

Rick

Reply to
Rick Courtright

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