Originally Posted by davalt75

My truck is straight stock with the 3.73 gears. I average about 13 mpg combination around town and highway. I drove it to the beach and back which is about 160 miles or so, round trip. Averaged 15 - 15.5. I live literally about 5 miles from Mike at 5 star Tuning. He's doing an 87 economy tune and and 87 performance/tow tune for me on Monday. Hopefully I'll be able to squeeze a few more miles out of a tank. It's a big, heavy truck with a big motor, though. I don't expect a huge difference.