I've never heard that one. If anything, I've heard it'* better to break an engine in with dino oil, so that it actually wears a little and gets things like rings and cylinder walls to seal well together. Once that period of break-in is over, then it'* ok to switch.

I have to think that the idea that you can't switch to synthetic without rebuilding your engine is a bit far-fetched. Virtually every engine filled with synthetic right now was filled with dino from the factory, with the exception of a few performance cars that I can think of.

I think the debate would end based on the posted experiences of the members of this Forum who have switched to synthetic, don't you?

Just switch. With over 5 years and over 5000 members here, we've never seen a single negative experience.



The above post about rebuilding and sticking with what the engine had......purely ridiculous. Again, we've NEVER had even a mild oil consumption problem on any car on this Forum that has switched. Rings and seals don't care what'* lubricating them. They care about sludge. This debate can go on and on, but the simple matter is you can switch to synthetic any time you want to. It is of NO advantage on a 3800, which are known not to have long-term high-mileage wear problems anyway. The only advantages to synthetic are:

1. Peace of mind.
2. Longer oil change intervals (use a premium filter please).

Pretty much. You get better protection also Bill.....You forgot that.

If you run Synthetic in a BRAND NEW engine, never broken in, your engine will take longer to break in do to the synthetic.....Which is why it'* said don't switch until 6-9K for gas motors.....20K+ for Diesels.....

Oh, and mixing oils, you can do it, but it'* definantly not recomended...

Synthetic Blend is blended at the plant it was brewed at, and designed to be together. Blended at best is probably NO WHERE near 20% synthetic, seeing how the minimum of 8% synthetics is required to even be called a "Full Synthetic," a Tier III grade oil.

Mixing the oil, each oil has a different additive package, and pretty much they're cancelling each other out, throwing the balance way off in the motor.....making the oil just about useless. If you wanna mix 2 qts syn and 3 qts dino....be my guest, but it'* not recommended and over time could more than likey trash your motor.

Nate, better protection?

Find me a Bonneville in our history here that ever had an oil-caused or related breakdown.

Find me a Bonneville here with 200-300k that doesn't have factory-spec compression still.

Our engines are NOT picky about the brand or type of lubrication. Some are, ours aren't.

I firmly believe there is no 'protection' benefit from synthetic oil in our application for these reasons. My UOA'* on Dino and Mobil1 were no different in the amount of 'wear' particles suspended in the samples. This is why I stated peace of mind as a benefit, not longevity or less wear.

It doesn't matter what you run as long as you run a reasonable oil change interval and premium or good-quality filter. Your engine will still outlast 3 transmissions barring any other failure (UIM/LIM failure etc).

:?: My engine will never quit then (and I run wally world oil)

Yes Bill, we know. You make mention to this in every topic that has to do with oil where I happen to make a post.

Hey, I don't really know if I had worded my last post just right. I was just letting you know of a myth I've heard, but it'* not my belief. I've switched engines over to synthetic after a lot of miles, and I think the previous owner kept switching back and forth from syn to dino depending on how he balanced his budget. I can't tell by the car, but it'* what I've been told. So there'* almost enough proof that synthetic switching is mythed out to be way more obtrusive than fact. So, I say switch!

It has nothing to do with you or where you post, Nate. I understand you have a product to sell, but you also understand that we have a responsibility to the members of this Forum to provide the most accurate information we can.

We've been saying the same things about synthetic oils and change intervals since long before you ever bought your first Amsoil product, much less became a dealer.

You and I have been friends a long time, but that doesn't mean I change my opinions on lubrication because you are now an Amsoil dealer. You have to respect my position here, and the responsibilities I have to the members of this Forum.

Until you provide proof that synthetic oils actually prevent wear in OUR drivetrains, and that there is some added benefit to a motor that is renowned for 200k and 300k lifetimes, the only TANGIBLE benefits will remain peace of mind and longer change intervals.

Careful ! Don't let the FACTS get in the way of being right about YOUR story.

It is clear that through all the mythology, there is little interest in what'* really the case.

The MOST important aspect to lubrication is REGULAR oil and filter changes.