Did you actually have an issue with synthetic oil in a car that hadn't run it for its first 100,000 miles or are you simply parroting the oft quoted urban legend regarding this issue? The truth of the matter is that you could drive a car a million miles on conventional oil and then switch to synthetic and it wouldn't make one bit of difference to the seals and gaskets.

 

what he^ said

 

I'm not parroting off anything. Two of my vehicles developed seal / gasket leaks when I converted over to synthetic oil. I switched bad to fossil oil - the seal leak on my Taurus went away. BTW, I worked for the company that produces the #1 brand of synthetic oil for 17 years of my career life. I hardly think I'd have a random bone to pick regarding synthetic oil.

Ken-Inn - Sadly, I've come across some of your other posts where on the other Mazda forum where another member suggested that you chill with a Xanax or something. Have you given it any further thought?

 

my car has only 49k miles & has a lot of little liks ?? wonder what we can expect from a 100k car ? ... only use syn once a year & to keep engine clean..it's practical ..

 

well, smart guy. how bout this? i will paypal the moderator 500 bucks. you do the same. then, the moderator contacts your, "I worked for the company that produces the #1 brand of synthetic oil for 17 years of my career life" company, and asks them. see what they say. cause anyone can claim they worked for such and such, which, by the way, does NOT make you and expert on anything. who knows if all you did was clean toilets? so, what about it, put your money where your mouth is. instead of spouting old wives tales. go straight to the experts. put up or shut up.

 

I've gotta say, I've been turning wrenches on cars for over 35 years and I've never even once seen a car develop any oil leaks after being switched to synthetic oil, even very late in the life of the vehicle. Do I believe that any one individual could have not one but two cars that deveoped such leaks? Yes. I also believe in the Easter Bunny.

 

I wish it were true in my case - where I didn't develop the leaks. However, I was a bit stunned when I experienced it. I even used the synthetic designed for higher-mileage vehicles.

I'll just stick with what works for me - even if it means more frequent changes.

 

I'm not quoting an "old wives tale" as you describe. I just listed out my *own* personal experience in dabbling with synthetic oil. Did I tell the world not to use it? NO! Again, I only described what "I" experienced.

KenInn, there you go again - way, way overreacting as you've done in other posts. You take this stuff way too seriously. These posts and transactions that occur here are not worth having a coronary over. Trust me.

 

A flame war? On MazdaForum? That's almost unheard of.
t2t, all I can tell you about Ken is that he is very helpful around here. He is one of the few that knows the Millenia models and usually jumps right on those questions.

For my own synth vs. dino oil impressions:
I too have heard the tale of synth oil getting by seals and gaskets, said to be caused by the smaller molecules found in the synthetic base. But I have convert over to it (Moble1) in a Honda that had +/- 80k on the clock, ran it to 190k w/o a problem. And there were times when I ran it to 15k before changing it. The car ran like a clock until the day I sold it.
My Mazda was converted @ 20k, has 60k now and still no leaks. I run Castrol Syntec 5w-20 or 5w-30 to 10k w/an oil filter change @ 5k.

And the 04 Mazda3 owners manual also states that synthetic is not recommended by Mazda, yet I know hundreds that do w/o a problem.

 

Really? Yikes, why did Mazda stay in the stone age so long? By the early 1990s most manufacturers had moved to language that says something like. "...the use of synthetic oil is acceptable as long as the recommended oil change interval is not exceeded." The Owner's Manual for my 2009 Mazda3 makes no stipulation either way; just make sure I used oil that meets certain API and SAE standardas, blah-blah-blah...