my 15.5 gets better highway mileage than my 04.5 did. by about 2mpg on a long trip, I can push near 20 on the 15, while the 04.5 was around 18.
But I've heard the 04 LB7 got better mileage highway then the 04.5 LLY
Now towing, can't say as there is any difference.
In town, again, both are about the same.
2015.5 Sierra Denali CC/SB/4x4 Stone Blue Metallic/Jet Black Interior
pinstriping by Bob Spencer AKA "spirit", undercover FLEX tonneau cover, color matched bug shield and vent visors, raintracker rain sensing wipers, X-treme coating bedliner, gm trailering camera system, coolant filter, Bilsteins, remote tailgate lock
04.5 LLY CC/SB/4x4 Allison Dark Green Metallic/Dark Charcoal Grey Interior
Webasto Hollandia Sunroof, Carbon Fiber Interior Trim, color matched bug shield & vent visors X-treme coating bedliner, Access roll top cover, Westin Step Bars, Lubrication Specialists Aux fuel filter, coolant filter, CAI, Michelin LTX tires, Manual High Idle Mod, Bilsteins, prodigy brake controller, raintracker rain sensing wiper controller, Remote autolocking tailgate, Reese Titan Class V hitch, Allison badges, Pinstriping by Bob Spencer, 4x4 decals removed, color matched door handles, 4 headlight mod, Homelink console.
97 Mercedes SL500, red with tan interior 97 Mercedes E420 sedan, royal indigo with grey interior 2001 KTM400EXC, 2011 Outback 295RE travel trailer
Last edited by ktmrfs; 05-20-2017 at 10:42 PM.