Fuel economy hmm. My 12 has never done better than 15 mpg. My 06 got the same. I like the 05 06 07 classic best, and the only reason i like 05 up vs. 03-4 is electric fans.
That's why I grab a few cases of chevron when its 9 off at Costco and I bought like 60 quarts on the o Reilly deal. It isn't like it'll go bad in my lifetime.