Just thought I'd update this thread. In the first 2 days I averaged 18.1 mpg with nothing changed other than being pretty cautious with traffic lights. My trip is 40 miles true highway and another 20 miles of 50+ mph roads with lights. I just ordered a magnaflow exhaust off of ebay for $200 shipped and will be swapping that out next week. For anyone interested, the awesome deal on the exhaust can be found
here