The dealer changed my oil 2 months ago. After about 3000 miles or so the system indicated it was due for another oil change. I thought that to be prety low but changed it myself last weekend. I reset the system and have driven about 300 miles. Now the monitor system says I'm at 90% life remaining. The manual says I shouls get about 9000 miles between changes or a little less depending on how I drive. My neighbor is the local maintanence director for the GMC dealership. Even he hasn't heard of that. Any ideas?