Pixie dust: Archoil fuel additive helped me gain 1 mpg while towing on my old Powerstroke diesel.
Unicorn wizz: Archoil oil treatment made minimal but measurable gains; again while towing with the old PSD. Between the two, I saw about 2 MPG increase...towing the same trailer on the same piece of road.
Otherwise, as others have stated, it's a matter of habits and discipline. Just because you CAN go 70 MPH uphill with a trailer, doesn't mean you should.
Towing and a lead-foot are the two biggest fuel thieves out there.

 

Not sure the size or make of your current tires, but when you are due, but they are one of the more measureable factors in the mpgs.

 

No they didn't.

 

"No they didn't"....what?

 

Archoil actually does some good in the diesel I run it in my 6.7 and 6.2 I haven’t noticed much difference using it in my 6.2 as I do in my 6.7.

 

Well, someone can say "No it didn't"...but how would they know since they weren't there?
I used my '97 PSD to tow the same trailer along the same stretch of road in the same year and by using the Archoil products, I got a slight but definite increase.
Believe it or not...doesn't matter to me. I have no affiliation to Archoil or any other manufacturer/dealer/supplier.

 

You know what I've found to be the best fuel mileage increase mod is to use top tier gas and bypass the discounted fuel. I won't even use Flying J unless it's branded as top tier, hard to find but they do exist.

Denny

 

Thanks for all the input. I drive like a light footed old man, because I am! My tires are small, 285/70-17 m/t and they even took some mpg off over stockers. I’m not up to speed with the aftermarket. I was looking to see if there was proven mods out there.

About the k&n, I drove the truck in stock form with the m/t tires and canopy for 2 years, 20k miles, mpg 12.2-12.3. I got the k&n cold air intake for Father’s Day June 2019. Same every thing else, mpg average holds at 12.8-12.9. I’m not complaining.

Why bother? 1-2 mpg is 10-20% for most. That’s a nice change for a fuel bill. My last new truck was 1994 f350 IDI. I chose 6.2 over diesel intentionally. If I find improvement I have time to benefit. Either way I plan to drive and maintain long term.

 

For the record, the mpg reflects no load no tow, same route daily. Chevron 87 fuel.

I imagine those of you with various routes and loads will experience different results and it would be tough to see small gains due to changing conditions.

 

How far are you willing to go with the mods? Lowering the truck will improve mileage. Removing the front driveshaft in the nicer months will help (parasitic loss from fluid in the front diff and t-case turning it). Putting your truck on a diet can also help...lose weight you don't need. Smaller F150 mirrors. Aftermarket exhaust (free flowing, lighter weight), etc...
How many miles on the spark plugs?
Run a bottle of injector cleaner through it lately?

 

Good point on the spark plugs and cleaner. Also don't forget to think about cleaning your throttle body and MAF. A GOOD tune up will help a bit. When I did mine back in the summer I picked up maybe .5 MPG on the highway.

 

lower the truck, change gears, small tires, remove non needed weight.

 

This may not help but yesterday I checked my filter that had only 6K miles and it was full of all sorts of crap, then I looked in the bottom of the box and it had a pile of seeds in it so somewhere on our travels we had small animal of some kind move in. Its on my summer list to pull the inner fender and hail screen the inlet. A few years back when I hit a pheasant it was full of feathers so hail screen can't hurt.

Denny

 

Some great points in this thread. The things I've found that yield the very best mpg's are,
1- accelerate softly from stop to stop.
2- tire pressure, I.e. Max them out, this has given the most improvement in mpg's for me. Yes the truck will ride a little rougher, but it's a truck!
3- rotating mass, everything the engine has to turn sucks horsepower, thus hurts mpg's, like, steel wheels, big heavy oversized tires, 2 piece steel drive shafts( I actually don't know if Ford uses this on a certain configure d super duty). With the dodge/cummins, going to 1- piece aluminum shaft made a YUGE difference!
4- total weight of truck, don't carry anything you don't have too.
5- speed, this may be the biggest point, keeping the speed down is Important, and I know it's hard when some of you live in a state with 75 mpg speed limits. These trucks are literally shaped like a brick.
that's all I got. ✌

 

my 14 actually gets better mileage at 75 than it does at 55.