SkiSmuggs

I have been towing with the Livernois 87 Tow Tune and have been using 91/93 octane whenever I tow. I have been getting about 10 mpg with cruise set on 60mph on the rolling highways of VT and NH. Since I got the Livernois update with 4 tunes, I went with the 89 tow tune and tried 6 hours of towing with 89 octane. My overall mileage fell to 9.5, so I am guessing the higher octane may provide better mileage for towing. I have seen no difference in non-towing trips and now run the lowest octane my tune will allow. As a result of this finding, I will use premium gas for towing as recommended by Ford.
I am aware that two things were changed, the tune and the octane, but doubt the tune is responsible for the drop as it should have more advanced timing vs the 87 tune.

brulaz

I wonder. There's not a big diff between 9.5 and 10 mpg. And I've noticed much bigger changes in mileage depending upon route, temps and especially wind.

SkiSmuggs

It was a route I've taken before and wind wasn't an issue. Even my wife commented on the mileage being lower than last trip.

RedOne

Mine is completely stock and I get 11 repeatedly. We are in relatively flatlands and only 500-600 feet above sea level so maybe that has somehting to do with it. But we are maybe thinking af heading to the Finger Lakes area in two weeks so I'll be able to get a better idea of overall mileage with the longer trip.

SkiSmuggs

Let us know on that. What is the weight of your fiver? Just checked online and yours is about 400 lbs less than mine, but also mine is a foot taller which probably makes the biggest difference.
I notice the uphill pulls use more gas than I get back on the downhill runs. Just had a BMW try to open a lead on a 3/4 mile uphill and I had no trouble staying with him at about 2/3 throttle, but my fuel mileage (reset 40 miles ago) dropped from 20.1 to 18.4 by the time he gave up. I wasn't racing and never tried to pass, but he was at full throttle. Guess we are both in our second childhood. :-) And I was really just cleaning the condensation out of the intercooler.

brulaz

That's just an Italian Tune-up

murf

Completely stock. 5th wheel is about 7500 loaded mayyyybee 8000 and constantly get 11 at 60 and almost 12 at 55.

Oh and my 6x10 open trailer always seems to net me right around 16 at 60, with a load, 18 without.

brulaz

Crikey.

I only get 12.3 mpgUS doing 60-62 mph with my little 4000# TT (+1000# kayaks and junk in/on the truck).

mbopp

11.8MPG on 2 trips with a 5000# trailer, canoe, generator, and firewood. No difference between 87 and 91 octane gas. 'Course it was fairly flat towing on both trips.

rikard

13 Mpg using 93 octane hauling my Cobra 25' 4500 lb fiver with truck in sig. on back roads of Maine at 55 to 60 Mph. Pin weight of 850 lbs. Truck pulled trailer much better with 93 octane and gas mileage was slightly better.
YMMV
rikard