I performed my first DIY oil change on the CT at 6200 miles. It's 9 months old so not a lot of miles since I also drive another vehicle several times a week. I was really surprise at how dark the oil was compared to the new oil. The odor from the oil was a fairly strong burnt note as it was draining, I didn't even have to put my nose too close to the oil. I don't drive my car hard at all.
Knowing this, I wish I had changed it 4,000 miles especially being the first oil change after break in. I know they say that the new cars these days with synthetic should be able to go 10k in between oil changes but I think my next change will be at 5k and will go from there. I have a tendency to keep my cars for a very long time so this is cheap insurance.
I would suggest that those who take it in for the 5k free maintenance pay for an oil change or DIY.
BTW, was there suppose to be a gasket on the drain plug? It was fairly dark under there and didn't see one. Do I believe that they always change the filter housing gasket that comes with filter? I doubt that they bother with it, that's why I DIY.
