Forum Discussion
60 Replies
Cummins12V98 wrote:
FISH thank you for the answer.
I don’t believe the trucks computer give 100% accurate mileage and I sure don’t believe the squeeze click test is accurate at all.
I do believe the computers would give a more accurate reading. Most display a more optimistic number.
I certainly would not bet any money the Ford gets 15% better economy. If RAM had those numbers I would say the same.
Fill tanks to TOP If you want to know reality.
I agree that the computer may be more accurate for short runs which this one was. If they had burned 20 gallons or more then I would be more inclined to believe the hand calculated number.FishOnOne wrote:
4x4ord wrote:
The problem with doing mileage tests over a short distance like this is that if during the test the Duramax happened to do a DPF regeneration and the Ford didn't the results are meaningless. I think it takes roughly a gallon of fuel to clean the DPF so on a run where only a few gallons of diesel is required the mileage result could be way off.
I thought about that but if a truck did do a regen I think the mpg delta between these two trucks would have been greater. Plus towing this much weight there should have been passive regen working in their favor.
I agree. Towing that much weight under that much load the truck should not have needed an active regen. I think the 3.42 rear end on the GM might have had an effect on mpg here especially if they let the truck do all the shifting.
My 2014 Ram 2500 also has a 3.42 rear and and while it is great for mpg unloaded, it is not so great loaded IF I let the computer do the shifting allowing it to go into 6th. If I lockout 6th and to in 5th(which is still an overdrive gear) then that brings my rpms up to the Cummins recommended rpms of 1,800-2,100 for most efficient towing in the 6.7L. Allowing the the computer to shift into 6th putting me at 1,500 rpm decreases my fuel mileage by about 1-2 mpg depending on the terrain.4x4ord wrote:
The problem with doing mileage tests over a short distance like this is that if during the test the Duramax happened to do a DPF regeneration and the Ford didn't the results are meaningless. I think it takes roughly a gallon of fuel to clean the DPF so on a run where only a few gallons of diesel is required the mileage result could be way off.
I thought about that but if a truck did do a regen I think the mpg delta between these two trucks would have been greater. Plus towing this much weight there should have been passive regen working in their favor.FishOnOne wrote:
Cummins12V98 wrote:
FISH thank you for the answer.
I don’t believe the trucks computer give 100% accurate mileage and I sure don’t believe the squeeze click test is accurate at all.
I do believe the computers would give a more accurate reading. Most display a more optimistic number.
I certainly would not bet any money the Ford gets 15% better economy. If RAM had those numbers I would say the same.
Fill tanks to TOP If you want to know reality.
On a sample of 1 you will never get a perfect answer. To be statistically significant you would have to make that run a minimum of 30 times under various conditions. Having said that it's becoming very obvious the 2020 6.7 PSD are getting better fuel economy from early reports including a Hot Shot driver who just switched from a '19 Ram to a '20 Super Duty and this test which is a sample of 1 still shows a trend.
A member i know on this forum got his 2020 - 6.7 and just emailed me this..
He ran just short of 60 miles (55 ) without towing and averaged 23.2 mpg. He just got the hitch installed and hooked up for a short trip yesterday with no fuel report. He did send me a pic of the truck level with 3200# pin- The problem with doing mileage tests over a short distance like this is that if during the test the Duramax happened to do a DPF regeneration and the Ford didn't the results are meaningless. I think it takes roughly a gallon of fuel to clean the DPF so on a run where only a few gallons of diesel is required the mileage result could be way off.
Cummins12V98 wrote:
FISH thank you for the answer.
I don’t believe the trucks computer give 100% accurate mileage and I sure don’t believe the squeeze click test is accurate at all.
I do believe the computers would give a more accurate reading. Most display a more optimistic number.
I certainly would not bet any money the Ford gets 15% better economy. If RAM had those numbers I would say the same.
Fill tanks to TOP If you want to know reality.
On a sample of 1 you will never get a perfect answer. To be statistically significant you would have to make that run a minimum of 30 times under various conditions. Having said that it's becoming very obvious the 2020 6.7 PSD are getting better fuel economy from early reports including a Hot Shot driver who just switched from a '19 Ram to a '20 Super Duty and this test which is a sample of 1 still shows a trend.- FISH thank you for the answer.
I don’t believe the trucks computer give 100% accurate mileage and I sure don’t believe the squeeze click test is accurate at all.
I do believe the computers would give a more accurate reading. Most display a more optimistic number.
I certainly would not bet any money the Ford gets 15% better economy. If RAM had those numbers I would say the same.
Fill tanks to TOP If you want to know reality. ktmrfs wrote:
agreed on the DEF useage. DEF consumption should be around 1 gallon/100 gallons of fuel. Can vary some, but 200 miles/gallon of DEF???? nope. something is amiss.
I wish I was getting 1 gallon of DEF for 100 gallon of fuel. The one time I did check it was 1 gallon of DEF for 42 gallons of diesel. 5 gallons of DEF in 2400 miles, over that 2800 mile trip we averaged just over 11 mpg. The L5P is a DEF hog!Cummins12V98 wrote:
Thanks FISH !
It was a honest question I knew you would know. Either they didn’t say what the Fords computer said for mileage or I missed it. Didn’t really want to burn up my hotspot for an answer I was hoping you would be kind enough to answer.
Really appreciate the help.
My honest response is I really don't care what the computers say for mileage when there's an actual hand calculated report and there's many here who will bash anyone reporting the computers calculated mileage. Having said that I recall it being 7.2 mpg.- Thanks FISH !
It was a honest question I knew you would know. Either they didn’t say what the Fords computer said for mileage or I missed it. Didn’t really want to burn up my hotspot for an answer I was hoping you would be kind enough to answer.
Really appreciate the help.
