Mutedduck

Just bought my 15 Sierra Club Cab, 5.3 Z71 with 3.08 gears. I'm averaging exactly 15mpg for the life of the vehicle at 2121 miles. I think that is fairly great mileage considering I bought the truck with 250 miles and proceeded to head to Atlanta towing my 16ft car hauler with steel deck to pick up a pair of Camaro's. 71 and 72 models. I had my friend tow another car hauler with his 13 Ram Double cab 4x4. Light load down at around 450 miles we both averaged around 15 mpg and loaded headed back I averaged about 13.2 and he averaged about 13.5. He had the better rear gear than my truck so I think that counts for the slightly better mpg on the return trip. Both trucks performed about the same if you ask me. I never hauled ass and left him and visa versa. We were averaging a net speed of about 78 mph on the return trip too. I haven't had a tank of fuel in her yet where I haven't had to tow my trailer or haul some stuff around. When I did go on a decent trip of about 120 miles light load I averaged about 18 mpg, but had to have it in Auto 4x4 because of road conditions. I filled my truck up just a few days ago and just after I filled it, I get a call from my brother to come pick him up because the wheel on his 69 Camaro came off on him while driving in the next town over. I hauled my trailer over there, ended up putting new studs on his car and he drove on home. I returned home and went to work the next day. He borrowed the truck to take parts to his body man and run some errands. A mixture of towing, hauling and stop and go driving with 142.5 miles took right at 7.2 gallons to fill up. That is just right at 20mpg. That is fairly good mileage out of a giant shoe box with wheels. I have no plans on lifting the truck or putting big tires on it as it is also a family vehicle, and from personal experience it is a B**ch getting a car seat in and out of a lifted truck. That being said, I wonder for those of you that have lifted your trucks, have any of you considered the fact that you have a 6l80 and it sounds as though it is an upgraded version of the 4l80, if you could do a torque converter swap. I know the factory converters on the 4l80e transmissions were huge and netted around a 35hp loss over the 60e. Just thinking it could get some of your power back. Or if you wanted to increase mileage a smaller converter would help there to as the rotating mass would be less. Maybe a converter, dual exhaust and maybe one range hotter spark plugs would bump up the mileage. Food for thought for those who don't care about their warranty.