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Post-towing MPG

5K views 14 replies 8 participants last post by  johndeerefarmer 
#1 ·
I bought my truck 8/31/15. 2013 F250 King Ranch 4x4 with 55k miles on it. The previous owner used it to tow a fiver and a pontoon boat. I picked it up and drove it home on a 2 lane country highway averaging 62 mph and 17.8 mpg. I finished that tank and 2 others and got between 14 and 17 depending on road/traffic. This is using the on-board calculator between fill-ups and my calculator at the pump. I towed my 35' travel trailer about 200 miles, and got 9.6 mpg doing it. Since then, I've consistently averaged 11.7 mpg in the same mixed driving I got 14-17 on 1.5 months ago. Short of disconnecting the batteries and letting the ECM reset, is there anything I can do to fix this abysmal fuel economy? I've been driving like a codger, coasting as much as possible, avoiding stop lights and busy intersections as possible, and still not getting anything better.
 
#2 ·
Part of the change is Winter fuel showed October 1st. And you won't get as good of mileage as the summer blend fuel. But you should not be seeing 5-6 mpg drop


Check your air and fuel filters.

Air pressure in tires

Maybe try a different brand of fuel
 
#3 ·
one of the things your generation and my generation of trucks share is the brake caliper design, floating on two guides. Those things notoriously bind up, sometimes to the point it's obvious (truck pulling toward the locked up caliper) but also to the point it just drags a little bit and doesn't heat up excessively, doesn't cause significant pull, and just slips under your radar...

it's my personal little theory that this happenstance is the reason for such a large mileage disparity between similar rigs doing similar things in similar places...

so... chock opposite wheels and jack a non-drive wheel of the ground, and give it a spin... as it slows almost to a stop, it should smoothly do so- not just stop abruptly.. it should also be able to be spun easily with one hand and not a lot of effort... look at the pads and the pad corners to see uniform (flat) wear... look for excessive dust on each wheel... or.. drive it for a while, and shoot each rotor through the wheel with an IR temperature gun and look for big differences...

long/short: I bet your brakes are dragging...
 
#4 ·
I never thought to check the brakes, I'll do that when I get home tonight.

I did think about the winter diesel, but I don't think we get that in Arkansas. I'll have to double check, but I don't think that's my issue. I bought a new air filter when I bought the truck, and I took the foam block off the outside of the air filter housing. I can put that back in if I need to, but since I do not do gravel or dirt roads, it's not really all that useful. Tire pressures are good, and I've only filled up at Sam's Club. I'll try a different fuel source next tank and see if it improves any.

Will SeaFoam, Lucas, or a cetane additive help any?
 
#6 ·
I jacked up the front wheels, and gave them an easy spin. It sounds like the brakes may be dragging a hair on both sides, but I'm not sure. I'm totally new to 4x4 also, so I don't know if it's the front differential dragging or if it's the brakes; the wheels only spun about 1 full revolution before slowing to a stop. I also went ahead and unplugged negative battery terminals for about an hour and gave the tires a few more pounds up to 70 just to test out. They were a hair low at 62. The drive back to work after lunch showed a slight increase, so at least airing the tires up helped.
 
#7 ·
I had a caliper freeze up and destroy a rotor. It is a fairly common problem. Make sure you put some grease on those slide pins when ever you have access to the calipers.
 
#8 ·
I got home from 9 weeks of towing and while my MPG is getting back to normal, it seems like the DEF readings are dropping faster than they used to. I got 5000 miles with DEF showing at 66% on the Edge and dealer topped it off with the oil change. It seems like I just got the 500 mile warning and added 2.5 gallons less than 1000 miles ago and Edge shows the DEF level at 70%. Since I don't record DEF use, it could just be in my head. I believe I went through 3 jugs of DEF on an 11,000 mile towing trip.
 
#9 ·
You getting a hell of a lot better fuel mileage than me. I get 10mpg regardless if I'm towing or cruising down the highway. I have noticed that I can get almost 13 mpg if I go between 85-90mph but if I drive speed limit and drive like a granny I get crap for mileage. I'm about to take it back to the dealer and ask for a different truck as I think it is ridiculous that I'm getting this type of mpg.
 
#10 ·
Do you ever reset the MPG display? After a few thousand miles on my trip, it took a long time to change the MPG on the display when not towing as the last tank MPG is combined with the MPG of the last 20 tanks. I had a ten day period without towing and the MPG only went up .5 during that time. Once I got home, I reset the display and it is slowly climbing and is at 18.5 in about 1000 miles without towing. It still takes a while as it keeps the history in its head and thinks the new MPG should be similar to the previous MPG. After the reset, MPG showed about 13 to start but kept climbing with non-tow driving.
Just to make things clear, my driving consists of 74 miles of rural (50) and interstate (70) daily. That means I don't make short trips and the engine gets to full temperature in 25 miles or so. I also use Opti-Lube Summer Plus and AR6200 fuel additives. It seems to help to NOT overdose the Opti-Lube, but hard to do with the bottle. I plan to use an old Stabil bottle for more accurate measurements. Soot seems to build up faster with accidental overdosing.
 
#11 ·
I reset trip A every fill up and trip B never gets reset. Yea it doesn't matter what I do I can get maybe 12 mpg and that was once then the rest have been 10 mpg and it is all hand calculated and not strictly by the gauge. I'm taking it to ford on Tuesday to see if they can figure anything out to why I'm getting such crappy mileage.
 
#13 · (Edited)
My 2013 F250 gets the fuel average from the fuel economy display. Have you reset that yet? The trip A and B get their info from the fuel economy. If you have not reset Trip B, it is cumulative. Same goes for fuel economy, it is cumulative if not reset and trip A will show same cumulative reading even though you reset it to 0. At least that is how my truck behaves. BTW I get 11-12 towing my 11K 5th wheel, 60-62 MPH, around town empty 17, highway @70 MPH 18-19. I use cruise whenever I can while on highway and towing. My truck is 4x4, 6.7L LB.

Don
 
#12 ·
I bought a 2014 F-250 Ultimate Lariat package, 16k miles at the end of August. Drove from Ft. Worth Texas, to Anchorage Alaska, in September, temperatures 20F to 95F. Best fuel mileage I got was 18.6 mpg on one run. On flat terrain, cruising around 55-60 mph, get about 18 mpg. Kick it up to 65-70 mph, drops to 17.5 or so. It seems counter-intuitive, but I get good fuel mileage in the hills, around 18 mpg. All highway driving. I have not noticed any significant affect on fuel mileage versus temperature.

City driving is another story with lots of stop and go. Routinely, 12-13 mpg, 25-45 mph.

Once it gets much colder, I may notice the temperature affect. Though, right now, granny highway driving in the hills is most efficient for me. If it wasn't for the inexpensive fuel now, City driving break me, lol :)
 
#14 ·
Yea I hand calculated it also as I write down every full fill up, mileage and the computer has always been within .1 mpg +/- I'm taking it to Ford to see if there is anything wrong and if there are any codes even though I know there aren't as I've ran my AE n it and my tuner that I use only for monitor and no tune is on the truck.
 
#15 ·
I assume the Super Duties are programmed like the ecoboosts. The engine runs different while towing (probably richer so that it runs cooler and safer). Once you quit towing it takes sometime for the truck to revert back to the non-towing mode.
 
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