Well, here is a update. The car has had 10W40 Mobil 5000 in it for the last month or so and has done considerably better than it did with either 5W30 or 10W30. I was only going about 700 miles or a little more before having to add a QT of oil but using the 10W40 I can now go about 1,200 miles or a little more. I have not noticed any difference in fuel consumption as it still turns in 32MPG or better every tank. I am just going to keep using the 10W40 Mobil 5000 in it and live with it.
Now if GM could just build a vehicle that does not nickle and dime me to death. Since I started this thread I have had to replace the master cylinder, the neutral safety switch, a relay for the cruise control, the horn, a power window actuator, the sun roof motor/gear box, the trunk latch, and do a brake job on the fronts. I know, the brakes are normal wear and tear. Just wish I had the same luck with GM's as I do with my Fords and foreign vehicles. I just change the oil, rotate the tires, and put fuel in them. All in all its still very cheap to drive and even though I hate it when things break I do love fixing them myself.
Chris
