It sounds like your issue is intermittent. Failing regulators will generally manifest randomly until they die out completely.

 

Hopefully the dealer will be able to isolate the issue without just sending me home.

 

I'm sure your dealer may figure it out however I would point them in the area of concern on what you think it might be so it's added to the notes and not overlooked. Intermittent electrical problems are hard to diagnose even for the dealer.
A load test of the charging system may point them them to a failed component.

 

Thanks!
I'll definitely make sure to mention exactly what you say. I appreciate your feedback!

 

Why are you using 93 octane ? Is that the highest you have in the USA ?? In Australia it's recommended to run 98 on the fuel filler flap which everyone I know does and there is no knock at any time or under any load condition .. 93 octane is very low and probably your problem . It's a high tech engine and deserves good fuel

 

93 AKI equals 98 RON. So he's using the Australian equivalent of 98 octane.

 

My owner's manual recommends 91 octane, and that's the highest I've noticed around here (SF Bay Area). I've experienced no knocking so far.

ETA: 91 octane (using the standard USA measurement unit) appears equivalent to 96 RON (research octane number), which is the measurement unit used in other parts of the world -- including Australia, perhaps?

Oops, better answer posted above. Still...

http://ask.cars.com/2008/07/octane-rating.html

 

93 AKI (98 RON) is available only in parts of the USA. Where there is not hot summer weather the top grade is typically 91 or 92 AKI, including where I live in Washington. In high altitude locations the top grade may be as little as 90 AKI. I always worry just a bit when I fill up in the Rockies and then drive back into the lowlands.