I bought a new 2006 Elantra in December. As a D-I-Yer, and former
mechanic, I've always performed the majority of the oil changes on my
cars. I always change oil and filter at 3K or 3 month intervals using
Mobil 1 synthetic. I fully understand Hyundai's requirement of keeping
a maintenance log, either in paper form or at hyundai.com's online
service log to show proof of preventive maintenance to maintain the
warranty. (Note: Using Mobil 1, and sticking to the 3K/3Mo. change
intervals, I've never experienced an engine mechanical failure in over
25 years of using the product).

Years ago, it was generally recommended to perform the initial oil
change at 1,000 miles. At that time, many cars used a "break in" oil,
but I'm not sure this is the case anymore. In fact, most cars had a
free scheduled 1,000 mile inspection, which included an oil change.
Nevertheless, it still may make good sense to initially change the oil
at 1,000 miles.

Any thoughts on this, pro or con, or should I simply adhere to
Hyundai's "severe service" drain intervals?

Also, since the current Elantra has a cast-aluminum sump cover, it's
most likely quite critical to torque the drain plug to a certain
maximum lb/ft. I wonder if any Elantra has suffered from a cracked
sump cover due to over-torqueing? This is a very critical aspect of my
SAAB 900, as a cracked aluminum sump cover requires replacement of the
entire lower section of the engine. Of course, this is thankfully not
the case with the Elantra, but I certainly could see problems should
the oil drain plug be over-torqued. Perhaps this is a question for
hyundaitech . . .