I have an '06 2wd with a 4.0L 6sp. We have about 2k miles and are getting 22mpg in mixed hwy/city. I try to run around at 2,000rpm and shift at conservative Rs. But I tell you what that 4.0L will run when asked! Also; I just got rid of a GM that never had anything but synthetic oil and never lost a drop between changes from burning and never developed a drip in 130,000 miles.
What do you think? Stay with the Syn. oil?
I think I will be going with the K&N air filter and a Flowmaster after the new has warn off.