Ya mine does the same thing too, with 134K on it, and she still pulls strong. I thought the same thing and I tried different oils to see if it made any change. Well, after a year now, I have gotten used to the problem, and the truck is as strong as ever.

 

Thanks for the input, I'm gonna try not to worry about it too much, hate to stray away from the Mobil 1 anyhow.