Tow/Haul/Def consumption
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Tuned
Joined: Jul 2020
Posts: 269
Likes: 27
Tow/Haul/Def consumption
My 21 F350 SRW Platinum eats def like a fat kid when towing our Momentum 5th wheel Toyhauler. I tow around 70-75 mph and try to keep the boost under 30% since I've been trying to find a work around. I use manual shift and for the most part spend most of my time in 9th gear. Peak tq is 1600-1800 rpm so I aim for that #.
So the last couple of trips I've been leaving the truck in regular drive mode and not selecting tow/haul. I select the engine brake and use manual shift unless I'm in traffic. The trans uses all the gears like in tow haul. Perhaps that's triggered by load sensing or trailer wire plug in. IDK.
I'm finding that I'm using much less DEF towing this way.
Any one else have the same findings?
My trips are usually from Scottsdale to San Diego over the 8, over the grapevine and up north AZ so lots of hill terrain and heavy load towing. Truck has 46k miles.
So the last couple of trips I've been leaving the truck in regular drive mode and not selecting tow/haul. I select the engine brake and use manual shift unless I'm in traffic. The trans uses all the gears like in tow haul. Perhaps that's triggered by load sensing or trailer wire plug in. IDK.
I'm finding that I'm using much less DEF towing this way.
Any one else have the same findings?
My trips are usually from Scottsdale to San Diego over the 8, over the grapevine and up north AZ so lots of hill terrain and heavy load towing. Truck has 46k miles.
5th Wheeling
Joined: Nov 2022
Posts: 29
Likes: 15
same here, 22 F350 SRW and when towing a 14kish 5th wheel it absolutely drinks the def. I simply put on t/h mode and engine brake and tow mostly interstate at 73mph using cruise control. I have not measured it but it feels like it uses def at least twice as fast as unloaded driving.
Lead Driver
Joined: Nov 2005
Posts: 8,485
Likes: 4,975
I never use tow/haul, and lock out 10th below 70 mph.
But DEF usage goes up as fuel economy comes down, they say DEF usage will be around 2-3% of fuel usage.
So, slow down when towing, 75 is very fast for towing such a big trailer, and DEF usage should be slightly less.
But DEF usage goes up as fuel economy comes down, they say DEF usage will be around 2-3% of fuel usage.
So, slow down when towing, 75 is very fast for towing such a big trailer, and DEF usage should be slightly less.
More Turbo
Joined: Sep 2009
Posts: 541
Likes: 199
I don't have my PowerStroke yet, but in my 2016 DuraMax DEF consumption is roughly 1.5% of diesel consumption. If you're burning almost twice the diesel towing a heavy 5'er at 73MPH vs empty, you'll be using roughly twice the DEF as well.
5th Wheeling
Joined: Nov 2022
Posts: 29
Likes: 15
I actually owned a 2016 DuraMax prior to the ford and never noticed the unbalanced usage between loaded and unloaded. The whole percent of fuel used makes sense and I have never measured it, but it sure doesn't "feel" like that holds when towing with the PS (I'm not arguing as I have not actually measured it, just an observation).
More Turbo
Joined: Aug 2005
Posts: 689
Likes: 216
I can definitely tell a difference when towing. At 65 mph there is much less used than when I crank it up to 68 to 70. Kind of interesting.
It's also interesting that the soot level goes down when towing and stays down. Definitely an indicator of how much the harder the engine is working when towing.
I can't tell a difference between tow/haul and normal. I usually stay in tow/haul but in traffic and stop-n-go I take it out of T/H as I think the low end ****s are a bit harsh.
It's also interesting that the soot level goes down when towing and stays down. Definitely an indicator of how much the harder the engine is working when towing.
I can't tell a difference between tow/haul and normal. I usually stay in tow/haul but in traffic and stop-n-go I take it out of T/H as I think the low end ****s are a bit harsh.
Hotshot
Joined: Mar 2017
Posts: 10,195
Likes: 1,385
From: Chaz
Whats your mpg?
Getting down into the 7-8mpg range and it will drink DEF and the distance to empty warning will get confused.
Getting down into the 7-8mpg range and it will drink DEF and the distance to empty warning will get confused.
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Thread Starter
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Tuned
Joined: Jul 2020
Posts: 269
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9-10 hand calculation.
usually some head winds going west. Huge grade up & over the grapevine/5 out of LA to Buttonwillow
Super Moderator
Joined: Aug 2008
Posts: 37,384
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From: Frederick, MD
heavy towing is more def consumption, has always been that way regardless of years.
Heavy towing means higher egt's allowing for passive regens this means there is enough heat to burn the soot as it is made. So no active regens depending upon model years or forscan mods or trim levels.
Bottom line is more def consumption to deal with the increased NOx. tow/haul on or off should not make the difference in consumption.
I always use tow/haul on mine as I am heavy and would rather use that then the brakes,
Heavy towing means higher egt's allowing for passive regens this means there is enough heat to burn the soot as it is made. So no active regens depending upon model years or forscan mods or trim levels.
Bottom line is more def consumption to deal with the increased NOx. tow/haul on or off should not make the difference in consumption.
I always use tow/haul on mine as I am heavy and would rather use that then the brakes,
Laughing Gas
Joined: May 2016
Posts: 997
Likes: 262
From: Central New York
NY to Florida with 14000 5th wheel DEF full. Filled DEF half way at truck stop with 3 gallons. Still full in Florida now. Travel at 65 to 68 and get 10.5 mpg. Truck regens at 500 mile intervals and hardly gets to 55% full each time. My 17 always went to 100% before regens but the 22 seems like the 500 mile interval is the priority.