The oil change interval recommendation for US-spec Hyundais is 7,500 MILES. The myth of the 3000 mile oil change refuses to die, despite the fact that there probably isn't a single car manufacturer recommending it anymore. The people recommending such short intervals are the OIL companies. They have a vested interest in you throwing out good oil and replacing it as often as they can convince you to do so.
If you think about it, what possible advantage would there be for a car company to recommend exteneded oil change intervals if there was any chance it would be harmful? Especially in the case of Hyundai with the 100,000 mile warranty, it would be suicidal. The car companies KNOW what is necessary for their engines. The oil companies only know what is necessary to pad their bottom lines.