If Rings Don't Seat:

[madmaxx]

The problem with syntheic is it rolls the tips/ edge of the cross hatches instead of wearing them down, in turn glazing the cylinders. It bewilders me with all the info available why anyone would use synthetic oil on a new engine. There is zero gain with synthetic, it will be changed before any of the additivies or oil could possilbe degrade. 20W50 is way to heavy, you want oil to flow through bearings etc not OVER them. I will never forget watching the oil flow over my rocker arms with 20w50 vs through them with the 10W30. It appeared more oil was flowing with the 20w50 but it was an illusion as we all know an oil pump is positive diplacment and displaces the same volume of oil iregardless of viscosity and pressure. Assuming you dont hit the internal releif in the oil pump with you 20W50 and it bypassed back to oil pan vs lubricating the engine. There is zero advantage to any oil over 10W30, nada only pain and future disappointment.