Our 2002 Avalon with 115k is due for an oil change soon and I am considering using Mobil 1 high-mileage 5w-30 instead of the usual PP. My reasons for switching are these: 1. I have noticed in the mornings on cold starts that a small amount of blue smoke is visible; this is not present when starting the engine warm. 2. I watch the oil level in this car like a hawk since it is the 1mz-fe. The oil level NEVER moves ... it is always on the full mark even with the small amount of blue smoke in the mornings. 3. I have read that the valve stem seal in these engines can allow a small amount of oil to "drip" into the cylinder overnight and result in a small amount of blue smoke. 4. We have had the car for two years now and it has been on a steady synthetic diet with PP being used the majority of the time. The PP is changed at 3k, so I seriously doubt any sludge formation. We religiouly change the PCV valve and when checking the oil on the dipstick it is always a nice honey brown color ... never black. So ... based on the above reasons would Mobil 1 high mileage 5w-30 be a wise choice as it may help swell the valve stem seals? I am partial to the mobil 1 brand high mileage as it is easy to find in stores and combines the high mileage seal conditioners with synthetic oil.