I towed a 33' outlaw 900 miles with my stock duramax around 70 to 75 mph and was getting 11mpg so 4mpg cant be right

When you have a tuner, you MUST hand calculate your mileage. The onboard computers are thrown off.

I transport boats 6k to 10k miles a month in my business (about 48k since Jan) . 5000 to 8500lbs , 30' and under. 65mph max speed ,1000 miles a day average. It takes a couple hours to get used to the slow pace, but its much,much easier on equipment . 5 trips Florida to Long Beach,California, loaded both ways and 8 trips Fla to Northeast with a !0 year old Ford Expedition w/HD tow package.

In my experience, tuners always make the duramax fuel economy output on the DIC read HIGHER, not LOWER than actual.


But I agree. I average 10.5-11.5 towing my Dominator 70-80 mph with my LML dmax.

I love MPG threads on this board. Nobody gives a damn about 1 MPG on the water but 1 MPG extra towing is a big deal.

Math:

$2.00 diesel / 10 MPG = $0.20 per mile
$2.00 diesel / 11 MPG = $0.18 per mile
etc....you get it

100 mile trip = $18 vs. $20

Towing at most MPG is the cheapest thing you'll do all day. Lord knows the beers at the local lake bar will surpass that delta super quick.

The DIC on my '04.5 LLY with w/60 HP Predator tuner would show 24 MPG. Of course, the DIC read high even stock. Usually 1.5 MPG to the happy side.

My wife is taking a job for 6 months in Ft. Meyers end of October and I am interested in doing something like this. Any info you could/would like to share would be great. PM me if you would rather keep it private.

Thanks,
Mike

15 hour days in a 10 year old Expedition with a 5.4 motor!.......whew that is torture:picard1:

Exactly^^ My 01 Ex w 5.4 could barely tow my pair of SeaDoos lol

I would think you must be right. I had to fill up three or 4 times from Concord NC to TNT in fla with a 42 gallon tank IIRC. What a pain in the ass to get in and out of stations with that mobile home behind me. Bad ball joints and not enough tongue weight had it all over the road above 70 mph on the return trip in 2012.