[jkib]

I have an 05 DC and run 285/17s in the summer and average around mid 16s for mileage. Have about 3500 miles now. This is a combination 50/50 highway and city. Haven't had a long road trip to check mileage for that as of yet--maybe soon though. Have filled the tank last two times with 89 octane gas to see if that might make a difference as it did in my old 95 Tacoma.
Truck turns about 2000rpm's at 70mph, as some have said to keep it at or below that for best mileage, and I usually drive with a light foot.