How do these engines get 'broke-in'?

Not open for further replies.
Sep 24, 2002
There is one thing that I've never understood or been able to rationalize. I've always heard that synth is soooo good it's not a good idea in a brand new engine because the engine needs to be broken in (valves, rings etc). OK let's presume this to be the case...

How does this allow for those engines that come from teh factory brand new w/ synth oil (e.g. the infamouse Corvette example among others)???

I've never been able to put those two scenarios together. Any help here...?


BTW if you ever visit the Vette factory in TN - just watch how they run the snot out of those cars right on the dino as they come off the line and then down a small test track 'course' and to the loading lot - WOT all the way! Break-in period indeed!
I assume that an engine which has synthetic as factory fill has had adequate precautions taken to ensure that synthetic is appropriate for immediate use. BTW, the Corvette plant is in Bowling Green, Kentucky. Saturn plant is in Spring Hill, Tennessee.

IMO, there is not much danger in switching to synthetic at the first scheduled oil change for most new cars. Now, let me qualify that: Honda and Volkswagen (and possibly other manufacturers) are both adament that the first change not occur until at least 5,000 miles have accumulated (or the specified time interval has passed), because they use a special break-in oil. Not sure about Honda, but on a Volkswagen changing the break-in oil too early is a guaranteed recipe for excessive oil consumption.
Afaik, the engines that come with sytnthetic from the factory are built to very close tolerances and the break in with dino oil is a non issue. Someone correct me if I'm wrong.
Also there may be a "break-in" additive in the original oil. This is specualtion on my part.
It is my understanding that cars coming from the factory have piston walls machined somewhat differently(hatching) than those that don't. Also, as observed, these engines are put through their paces before they leave the factory. Given the majority of break-in occurs(or should occur) during the first 20 miles, they are pretty much broken in as they leave the factory. The rest of the break-in is primarily bedding in of all parts(vs the piston rings seating) and that should involve multiple heating/cooling cycles.
I don't see a problem because I honestly do not believe a synthetic oil is any more slippery than dino oil. The base oil is not really going to affect things as much as the additive package will.
So there are a lot of dino oils and blends out there which are more slippery than some oils labeled as synthetic.

[ September 28, 2002, 04:16 AM: Message edited by: Patman ]
Not open for further replies.