Impact of Heavy Duty Tow Package (w/ 3.73 axle ratio) on MPG gas mileage

[Fozzy]

consider yourself doing well!

our '17 F350 (crew cab, long bed, 4x4) 6.7L Diesel w/ the 3.55 gearing couldn't get 17 on the interstate...UNLOADED (houston to virginia and back) at posted speed limits!

I bow to you sir. That sounds like an honest fuel mileage report. I love the 6.7 but I have not had a diesel get over 20 honest MPG no matter what brand since my 2003 Cummins. You know the three things guys like to lie about? 1-How much they payed for the truck. 2- the size of their junk 3-how good their fuel mileage is.


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[MxRacer965]

I bow to you sir. That sounds like an honest fuel mileage report. I love the 6.7 but I have not had a diesel get over 20 honest MPG no matter what brand since my 2003 Cummins. You know the three things guys like to lie about? 1-How much they payed for the truck. 2- the size of their junk 3-how good their fuel mileage is.


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Too much pollution crap on them nowadays?

I’d love a diesel pickup but just can’t justify the initial purchase difference, excessive fuel cost, and lack of fuel efficiency. I don’t tow anything heavy so no need there...

 

[Deadman]

The new diesels are ruined with the EPA stuff.
I'll keep my 2006 pre-emmissions until it dies.....

 

[bushpilot]

I bow to you sir. That sounds like an honest fuel mileage report. I love the 6.7 but I have not had a diesel get over 20 honest MPG no matter what brand since my 2003 Cummins. You know the three things guys like to lie about? 1-How much they payed for the truck. 2- the size of their junk 3-how good their fuel mileage is.


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my 2004 6.0L (same config, long bed, crew cab, 4x4 w/ 3.73 ltd slip) got better mpg

 

[bushpilot]

Too much pollution crap on them nowadays?

I’d love a diesel pickup but just can’t justify the initial purchase difference, excessive fuel cost, and lack of fuel efficiency. I don’t tow anything heavy so no need there...

you got that right!
I wasn't gonna put 3k more into a 75k dollar truck just to get some marginally better mpg.

ford DPF Regen strategy screws the mpg...every 500 miles, regeneration occurs needed or not (if I hammered on it, I could make it regen every 90 miles).

it was 4* (f) out, the filter was showing only 30% full and because I hit 497 miles (since last regen) the system went into regen...absolutely killed the mpg.....loved that truck and the range was good w/ the 50g tank (I could still get 700 miles between fill ups on interstate trips)....but it was far from flawless w/ only 27k miles on it, I was DONE!

 

[bushpilot]

The new diesels are ruined with the EPA stuff.
I'll keep my 2006 pre-emmissions until it dies.....

not all of them...it really depends on the strategy...friends w/ a pusher motor coach haven't seen a regen in 6000 miles.

 

[JasonH]

I don’t tow anything so it wasn’t worth the added expense to me. I know folks on here mention a trans cooler, but the Ford literature nowhere states that you get one of those with the Hd tow pack; the previous gens did, but I don’t think this one does. You get an upgraded radiator and a locker, but nothing says anything about a trans cooler. And if you don’t tow or need the locker, I just don’t see justifying the expense of the package. I’ve had mine for 2+ years and 30k miles and I’ve never missed the tow pack.

Looks like JL1Z-7A095-B is the transmission cooler part number.

 

[aggiegrad05]

Looks like JL1Z-7A095-B is the transmission cooler part number.

But I think that comes on all trim levels/packs, not just HD tow.

 

[wakeboarder]

OP below is a screenshot for my fuel mileage spreadsheet. It is mainly city driving. 40 to 50 mph speed limit with stopping at stoplights etc. a couple times per mile. You can ignore the mileage for the break-in. I usually fill up before 1/4 tank.

 

[Old Guy]

I am a retired engineer and expressing my thoughts.
I don't have a gen 4 expi. I have a gen 2 (2003, 5.4, 4X4 HD tow package. I get 10 everyday around town, and 16 on the highway. Mine is paid for and I will not spend 50 grand to get better MPG. I can buy a lot of fuel for that.
Engines have a RPM band that we call the sweet spot. This is because of the engine, the vehicle, and the driver. The difference in axle ratios is somewhat insignificant with a 10 speed tranny, or a variable ratio tyranny (which I hate). It and it's related computer, will analyze the vehicle speed, load on the vehicle (wind resistance, climbing a hill, towing, etc) and put the tranny into whatever gear to maximize performance and MPG. It actually does this many times a second.

Because my vehicle is my everyday driver, and once or twice a month I tow 7500# (boat) as much as 200 miles round trip. (Hey, that's why one buys a trailable boat, right?) What I would like to see data on is: the MPG differences while towing for the different engine/tranny combos, including the diesel.

My $.02....

 

[bushpilot]

I bow to you sir. That sounds like an honest fuel mileage report. I love the 6.7 but I have not had a diesel get over 20 honest MPG no matter what brand since my 2003 Cummins. You know the three things guys like to lie about? 1-How much they payed for the truck. 2- the size of their junk 3-how good their fuel mileage is.


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@Fozzy - you should hang around an RV park...more MPG lies told there (cummins guys seem to be the worst) that anywhere...im on one forum now where someone claims 22mpg when towing his 30' 5th wheel.

ill assume most folk cant do simple division to determine actual mpg - cause their lies are so bold NO ONE believes 'em!

On my 2004 (6.0L) I had 3.73 rears and installed a GearVendors Double-Over drive...in the end it was the death of the 5r110 tranny...it was a lot of fun on the interstate....right in the rpm/torque curve sweet spot at 80...but it lugged the motor below 70....I could get 22mpg outta that truck (and had a 50g tank in the bed....gave me a tank to tank range of over 2000 miles (wife hated road trips in that truck).

 

[Paddler]

I have a 2018 Max, no HD tow package. Wouldn't have it, as my boat is under 4000#. I average a bit over 20MPG, much better on the highway. The tow package is recommended only if you tow more than 6000#. Doesn't make sense to me to pay more for something you don't need that hurts fuel mileage.

 

[LokiWolf]

I have a 2018 Max, no HD tow package. Wouldn't have it, as my boat is under 4000#. I average a bit over 20MPG, much better on the highway. The tow package is recommended only if you tow more than 6000#. Doesn't make sense to me to pay more for something you don't need that hurts fuel mileage.

Cause you get an ELSD, 3.73 gears and a low range. Oh and a bigger Radiator.

Yours a 4x4?

Average more than 20MPG, according to hand calculations or the Computer?



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[Paddler]

Cause you get an E Locker, 3.73 gears and a low range. Oh and a bigger Radiator.

Yours a 4x4?

Average more than 20MPG, according to hand calculations or the Computer?



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Mine is all wheel drive, which makes sense as the wheelbase is really too long to be a fully capable rock crawler. I can get where I need to go to hunt archery elk, which is what really matters. Don't need a low range with the 10-speed transmission, cooling isn't an issue, so I'm good.

Hand calculated, mixed city/highway, drive like a grandpa. 63MPH on the freeway, not in a hurry. No BS. The computer is about 5% optimistic.

 

[LokiWolf]

Mine is all wheel drive, which makes sense as the wheelbase is really too long to be a fully capable rock crawler. I can get where I need to go to hunt archery elk, which is what really matters. Don't need a low range with the 10-speed transmission, cooling isn't an issue, so I'm good.

Hand calculated, mixed city/highway, drive like a grandpa. 63MPH on the freeway, not in a hurry. No BS. The computer is about 5% optimistic.

HaHa, on the Low Range. Still improves the Torque and crawl ratio. Not rock crawling either. Yes, 10 Spd helps, because you can have a lower 1st and more OD’s, but it does not take the place of a true Low.

Nice on the MPG. I like the skinny pedal, so I will never see that. Nice to know it is capable of it!


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[Fozzy]

You would be pulled over or rear ended on our freeways at 63. The interstate is 70 in towns and 80 on the open road. Belt loops are 70 now. Cruising at 80 MPH kills fuel mileage. I mentioned my old 2003 Cummins would get 20 MPG. Speed limit was 65 and you would chance it by going 69 MPH. I pull my boat at 80 and don’t even think about it. Makes me wonder if I still had that truck and ran it at 80 what it would get. Every Cummins since would get 13 mpg up a hill, around a hill or down a hill.


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[Paddler]

I stay in the right two lanes. People blow my doors off, but I'm cool with that. Speed limits here are 70MPH, 80MPH on the Interstates outside of metro areas. I don't use my brakes much, either.

If I can't get somewhere in 1st gear and AWD, I get out and hike. Using the quads God gave me.

 

[Lou Hamilton]

You would be pulled over or rear ended on our freeways at 63. The interstate is 70 in towns and 80 on the open road. Belt loops are 70 now. Cruising at 80 MPH kills fuel mileage. I mentioned my old 2003 Cummins would get 20 MPG. Speed limit was 65 and you would chance it by going 69 MPH. I pull my boat at 80 and don’t even think about it. Makes me wonder if I still had that truck and ran it at 80 what it would get. Every Cummins since would get 13 mpg up a hill, around a hill or down a hill.


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Until recently (last 2-3 years), max towing speed in most states was 55.

I grew up towing large construction machinery -- Mid-70's International Loadstar dumptruck, flatbed trailer, and International backhoe loader (Yes, my family liked International products as we also had tons of Scouts). I was raised to tow slow then and I still do.

I stay in the right lane and maintain my 55-60 speed all day now with my camper.

 

[Artie]

I stay in the left lane and maintain my 55-60 speed all day now with my camper.

For your safety and sanity of others I sincerely hope you mean the right lane and not the left lane.

 

[Deadman]

For your safety and sanity of others I sincerely hope you mean the right lane and not the left lane.

Ya, that's illegal in some/most states....