My origonal plan was to get a new engine all together. I was reading on those sites that they can use the old engine as well. I see that they have engines to replace mine....I just misread it. I intend on getting the engine flush and tranny flush in the mean time b/c the earliest that I could do this switch would be early next year. I use Mobile 1 that's synthetic. The thing is, I bought this car used at 30,000 miles on it and its now at 66,000 miles and I have no notion of what the previous owners used or how they maintained it. Other than the tranny filter change, I've kept up with the maintainance.