Snoopy

Stryker....

Change to synthetic oil any time before an engine is ready to blow (tongue in cheek). As long as you have no inherent problems.....bad gaskets, seals, etc.

I never believe information from people that got it from a person, who knew a person, who has a relative, who has a next door neighbor, that has a friend, that is a delivery man for the company (ZTony...you are unbelieveable. Being a 30 year partsman, you probably have access to GM Research data related to this very subject. I suggest you read it. What you are proclaiming is antiquated, to say the least. It was many decades ago when that statement had SOME validity).

I switched my GD's car over to synthetic at 55,000....it now has almost 70,000.....no problems.

As JoeR says....just do it !!!

sleeper

Another old rumor with with no facts supporting it ..

You can switch back anytime....Again no special rituals.. Just do it..

Hotrodbob

6 months ago I switched my all original '71 Ford Maverick to Castrol Syntec 5w50. No problems and the engine idle had to be turned down after a few weeks of driving. Lifters are even getting quieter. Switched my Vette with 75k miles to Syntec and it was great. I have never had an oil issue with changes to synthetic oils or lubes. I run it in the trans and rear ends as well on my RWD cars. I started using sythetic oil in 1977 on a SCCA H/Prod Healey. Loved it ever since.

ZTony8

Snoopy,the info I got was from our oil supplier,within the last 10 years.And we at dealer level don't have access to the info you might think we have.