To start with, every engine (at least 25) that I have built in the last 10 years started with synthetic oil & never had any problem with break-in. Or had any oil related consumption problems.

EVERY MB that leaves the factory & has so since 2001 has synthetic oil in the engine...break-in isn't a problem.

I would think that a std 15W-40 would cause more problems(wear) as it doesn't have good lubrication properties in cool to cold weather.

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