SkiFast

......no visible oil use up to 5000 mile service & oil change, now due for 10K service. Had to add a good half quart between 5K and 10K. (Not aware of what type of oil dealer used, would suspect it wasn't synthetic)

What is the explanation for this? Is there a definitiv difference with oil use on non-synthetic or syntethic oils? Should that use diminish with more miles on the car?

JBaumgart

I have never heard of any difference between synthetic and non-synthetic oils as far as their propensity to burn oil - they should be the same as long as their visosities are the same (heavier oils should consume less). Question: did you happen to check the oil level right after the dealer changed it at 5,000 miles? I wonder if they left it a little short of full at that time.

Also, from what I understand and have seen from the posts on this board, it is quite common for this engine and all turbo engines to consume some oil, especially when new. But the rate of consumption should decrease once the car is fully broken in. I don't think a half-quart to a full quart every 5,000 miles is anything to be concerned about, even after it's fully broken in. Even my old non-turbo Grand Cherokee consumed oil at about this rate, starting from when it was new until I sold it at 98,000 miles.