Does anybody have the 5.3L V8 in the new 2007-2008 silverado's? I'm looking at a new chevy 1500, and its got the fuel management system where 4 cylinders cut off when not in need. Does anybody tow with this engine on a daily basis? How is the fuel efficiency? They claim 15/20 on the sticker. I got a 16ft enclosed trailer that I tow with the 4.3 V6 right now.