Anyone running Synthetic in their HHR? Mechanics at the dealership have no input on the issue (I suspect they have no information or experience to back them up if they tell you "yes" run Synthetic or "no" dont). My questions are: Will the extra expense of Synthetic be returned by longer oil life? Better MPG? Less engine wear? How will this affect operation of the DIC oil life meter? My understanding of the oil life meter is that it takes certain operating parameters and uses the information to determine oil life. If it isnt adjusted for Synthetic will it have you changing the oil to early? On a side note has anyone heard of the Engine Management Computer storing long term maintenance information that can be retrieved only by the dealer? Like how many miles you drove between oil changes (at least how long between reseting the DIC) or other maintenance information that tells when and if certain maintenance was performed on time?