I know this issue has been beat to death, but I found some interesting information regarding break-in periods on the LGX engine. The 2017 Buick LaCrosse is fitted with the same LGX engine (albeit, de-tuned) as the V6 Camaro, however there are no MPH or RPM restrictions for the Buick's break-in period. Furthermore, the break in period for the LaCrosse is listed at 500 mi. Seems strange that the break-in period for the Camaro is 3x longer than for the LaCrosse with the same engine.
See link below:
http://www.buick.com/content/dam/Bui...se1stPrint.pdf