How often do you have to change the oil in supercharged 2002 Grand Prix GTP?

I believe you are asking about changing the supercharger oil. The dealer has no specification/requirement to change the oil. However many people change this oil on a yearly basis. You will need to pump/suck the oil out and replace it with GM supercharger oil only. ( a turkey baster or a spray pump is a good DIY device for this task) For step by step instructions check out the following website. http://www.oqcgp.com/forum/kb.php?mode4 Hope this helps "G" Currently this is the link for above procedure: http://www.oqcgp.com/forum/kb.php?mode=article&k=4&highlight=supercharger Happy oiling! "b"