New car break-in period?

[mmutte]

For the mechanical engineers/car guys...

Does this still hold true for newer cars? I didn't think it was still needed...

I purchased a 2015 Yukon XL June 2015, brand new.

This past week I was looking through the owner's manual to figure out the towing capacity, and ran across the page instructing me to stay under 55mph for the first 500 miles. Let's just say, I didn't do that...

A week after purchasing I took it on a road trip and didn't stay under 55 mph for the first 500 miles. I have put just under 17k miles over this past year and it has done great. I love driving it and havent had any issues thus far(knock on wood).

Something that leads me to believe it's no longer needed is that during the test drive the dealer had me take it on interstate for about 15 miles and we definitely didn't stay under 55mph for that drive.

So, is the life of the engine at risk? or is this nothing to worry about?
Thanks for the input

Matt