I've heard that the white-block engines will never have the longevity of the red-blocks -- different design parameters. But that said, let's consider what you have:

A sudden increase in oil consumption (re "...In the last 5,000 miles....")points to some failure, not merely a matter of gradual wear. And 1 qt/500 mi is a lot! If you can't find a leak anywhere, I'd bet that your turbo is toast! They're notorious for failing, and sucking oil in the process -- have you always used synthetic oil, and let it cool down before shutting it off? Turbo's need TLC, much more so than a N.A. engine.

But this blaming the turbo is merely a guess.

Why not just go to a dealer (a different one, unless you left on good terms with your regular dealer) and just say that you've experienced a sudden increase in oil consumption and you want them to diagnose the problem. Don't talk about warranty or anything about blame. Act innocent! See what they say.