New Engine, When to Switch to Synthetic

[wildjyoung]

Hello,

I have a newly rebuilt engine with about 4 hours on it. At what point can a safely switch to a high quality synthetic?

Thanks!
Josh

 

[brandini]

1k milesish-

After you're fully warmed up do some good 90% runs and push the engine and baby the trans. Then swap over and never look back.

 

[expat]

If it were me, I would do a couple of short OCI's first on cheap Dino.
Because I would not want to dump synthetic after only about 1K.

 

[hate2work]

Many cars are now coming with syn from the factory, switch whenever you want, no worries.

 

[Eddie]

I've always switched over at the first oil change at ~ 2-3,000 miles and never a problem. I usually drive my cars out to ~ 125,000 miles and never experienced any oil related issues.

 

[nfs480]

You can switch whenever you want, frankly i'd wait until the first scheduled oil change solely to get your money's worth out of the initial fill and not be wasteful. But beyond that there's no reason you can't switch to synthetic right away.

 

[marvinlee]

The only plausible non-cost reason I've heard for not using synthetic from the start is a claim that some car firms use a special break in oil that provides additional anti-wear properties. I've never seen the slightest proof of that claim and wonder if it is valid. Others have argued that synthetic should be avoided because it is too slippery and thus impedes engine break-in. I disbelieve that claim, and again have not seen proof. The most common synthetic oil chemistry is PAO and it has no superior anti-friction properties compared to standard oils. It does have other, favorable, properties.

 

[XS650]

Originally Posted By: hate2work
Many cars are now coming with syn from the factory, switch whenever you want, no worries.


Rebuilts and factory are two different things. Say what you want about car manufacturer quality, the average machining work in a new engine is better than the average rebuilt.

Unless you really know how good a job the re-builder did, assume there is more machining in place as the engine is broken in on a re-built than on a new one.

 

[UNC038]

Originally Posted By: XS650


Rebuilts and factory are two different things. Say what you want about car manufacturer quality, the average machining work in a new engine is better than the average rebuilt.

Unless you really know how good a job the re-builder did, assume there is more machining in place as the engine is broken in on a re-built than on a new one.



I agree, I would to a a 1k and then 3k intervals. At 10k switch to synthetic.

 

[cousincletus]

I agree with 10K also. I have seen a fair amount of metal come out of a rebuilt engine for the first few changes. My 2001 Dodge 1500 p/u (3.9 V-6) had a little fine metal and other grit come out of it until the third change, and that was a factory engine. After it broke in, it never used any oil, so I'm thinking it was broken in right.

 

[ARCOgraphite]

Originally Posted By: wildjyoung
Hello,

I have a newly rebuilt engine with about 4 hours on it. At what point can a safely switch to a high quality synthetic?

Thanks!
Josh
why do you want to switch? And what is a high quality synthetic?: Redline?, Fuchs Silkolene Pro S? Pentosin? Total/Elf Quartz Energy 9000?, Amsoil ATM?