I have had a few people tell me that they are getting 20+ MPG with a handheld tuner and no other mods. Possible? Or just BS stories?

If 20+ is doable, I would like to find a extended cab or crew cab 2WD 2500 HD for a DD.

 

If you are on highway constantly, then yeah but normally average somewhere closer to 16-18.... And in my experience they tend to handle and get better fuel mileage loaded, especially the duallys

 

I kind of figured, I did some reading online and most people report 15-17 MPG.

What about the older trucks? I saw a few people with 95'-99' obs 6.5L trucks reporting 21-24 MPG. I would not be opposed to one of those. I am looking for something that gets better mileage than my 2001, has more room, and can tow a car trailer on occasion.

 

I know my LMM dually with EFI gets 16mpg on average, unloaded. I drive it every day except the weekends. I keep it on the 100hp tune.

 

Ours aren't far off mine usually 17-17.3 hand calculated and it's my daily and I drive on my biggest tune and mines twinned on top of it dyno says 637hp so for that Hp I don't think it's bad my lbz used to get better Mpgs then my lmm hands down. If I was the ip lb7's are suppose to be the best mpg dmax but also have the injectors issues. Just my 2 cents.

 

Your Dmax isn't gonna run very well on gas haha.

 

I caught that as well but left it alone...

 

My 13' dmax with custom tunes, intake, and exhaust did about 14-15 city, 21-22 mixed. Best hwy mileage I ever got was 25mpgs if I remember correctly.

 

If you eliminate all and I mean all of your emissions equipment, drive like a grandma, have a good economy tune, and the planets are in alignment then yes it can be done. I am driving my mother in law's truck around right now. It's a 2011 with a leveling kit, 35's, a good eco tune, and all of the emissions deleted. It said 15.7 average mpg when I first hopped in it. She drives pretty aggressive for a big truck, but I would say that is about what most people can expect.

 

I've nvr seen A duramax get better then 22-23 and those are all
Lb7's which get the best Mpgs out of the dmax not lml's. Lol