69er

KJL's thread "Synthetic oil and cork gaskets...is this a problem" brought this question to mind.

It seems many feel synthetic oil shouldn't be used on a new engine or fresh rebuild so with that in mind wouldn't that prove synthetic oil protects better than dino oil?

Tom454

IMOP-
Nothing is going to *prove* that synth is better than dino except a well documented, independent, reproduceable, properly constructed test.... which I have not yet seen. They always skip or ignore the "dirt" issue.

Personally, based on the products "specs", I believe synth is a better oil.

However.... I did my own test... (I am an egine builder)

I used synth oil on a fresh engine and compared it to dino oil at the 3000 mile mark.... the synth oil was just as dirty (visually) as dino oil.
"Dirt" is not the only thing that contributes to engine wear, but it is high on the list.
I did not do a chemical contamination test... irrelevant for my purpose.

So... since synth oil gets just as "dirty" at 3000 miles as dino oil, I feel compelled to change it at 3000 miles.
This defeats one of the main benefits of using synth oil... longevity.
So, I came to the conclusion that synth oil is not cost effective for those of us on a tight budget.

(I also buy $5.95 watches at WalMart and throw them out when they quit. Rolexes don't impress me. :)

69er

Tom what about synthetic oil not letting engine parts "break in" on new and rebuilt engines?
Doesn't that show synthetic protect better?
Not busting your chops ...just wondering.

Tom454

Well...

All I can say is that I have been building engines for about 36 years and have been using dino oil...
I have not had any problems with break in or long term wear. I have re-visited engines that I built after 200,000 miles of wear. Given regular oil & filter changes, dino oil works just fine.

In my opinion (and remember, this is only an opinion), synth oil is a lot of hype.

It is a good product, and based on the specs alone, is better than dino oil.
But the cost/benefit part of the equation is not being portrayed accurately simply due to blow-bye contamination issues.

That's why I made the watch reference.... some people just gotta have the best...
the rest are frugal like me.

Now remember... I did not say that dino oil is "better" than synth oil... just the opposite.
I refuse to drive around with dirty synth oil after 3000 miles just because some test shows it lubricates better than dino oil.

If you want the best of both worlds, use synth oil, but change it out at 3000 mile intervals. (If you do your own oil changes, you will see how dirty it gets).
That's just not cost effective for me.

69er

Tom I appreciate your replies.
I think the greatest advantage with synthetic over dino is a cold weather start.
Other than that dino is probably just as good.
Just that break in engine thing always made me think it was better because parts don't wear in properly with synthetic.

GTR1999

Joe, I have used Dino oil in my 94 S10 since new, Change every 3k miles and now have 208,000 on it without any engine problems. The tranny lasted 118k miles but the engine still runs strong and doesn't use oil. Inever rna synthetic oil in any car and have had very good service as long as I changed it often.
Gary

Monkeywrench

I have read "take it with a garin of salt" that synh oil has a tendancy to find it's way into smaller gaps in gaskets as compared to dino oil. Hence on an older motor it would leak more.

Like I said... take it with a grain of salt...