I am new here so feel free to flame me but I have been reading alot of threads on here the past couple of days and some seriously intelligent guys on here. I have a my personal shop truck is a 05 single cab short fleet with a 4.3 v-6 auto in it. I sold my powersmoke diesel with a 7.3, air intake, exhaust, tune, a 6" lift 4wd with 35 tires so I can save on fuel when I started my business last year. The problem is they BOTH get/got 13mpg. Is there something wrong with my 6 cylinder!!!!!!!!! Even hypermiling I only get 15mpg but it sux sitting in traffic with the truck turned off. Any help with this would be greatly appreciated. I hope this is the correct place to post. If not mods feel free to move.