Join Date: Oct 2009
Location: Altamonte Springs, FL
Break-in nowadays is more for the differentials and transmission than it is for the engine. The engine is broken in at the factory with the engine hanging on chains outside of the car. The full drivetrain with all parts assembled (engine, tranny, and diffs) does not come together until the assembly plant, and it is the drivetrain, with all linkages in place that needs to be "broken in" before being abused.
Follow the user manual breakin procedure and give yourself the peace of mind knowing the parts meshed as they were meant to. The most common complaint that I have heard that can be related to holding steady speed for long period during breakin is gear hum coming from the diff. This is because the gears wore in at a constant speed rather than wearing across the board. This can cause the gears to whine or hum softly at that speed in the future.
If you are going to be doing highway driving during breakin, just vary your speed up and down by 10MPH, and if you have a manual tranny, downshift to 5th and run in 5th for a while every now and then.
Paul R in Sunny Orlando
2010 Victory Red SS/RS
Last edited by Paul R; 11-16-2009 at 08:06 AM.