MPG Indicator vs Math
Senior User
Joined: Jul 2006
Posts: 385
Likes: 2
From: North Florida
I run my mileage on trip 2 and reset it every fill-up. I don't hand calculate anymore but I did every fill-up for a while. I always got anywhere from .3-.5 MPG less with my hand calculations.
New User
Joined: Aug 2017
Posts: 21
Likes: 0
From: Tucson, AZ
Nimrod,
Yes, I do reset Trip2 (not Trip 1 - totals from purchase). BUT I also just installed a TransferFlow 60 gal tank to replace the 34 gal factory tank. I understood that the factory tank still had about a 5-7 gal reserve when registering empty. The new tank is deeper (removed the skid plate) and longer, SO when registering empty on this first tank full with the original gas gage, I was wanting to calculate the fudge factor and drive it near empty. Hence, the MPG calculation. I do think the average MPG is calculated off the gas gage which is now rather inaccurate. OH WELL, the full use of the first full 60 gal tank will tell the real story. More later when I run through this first tank.
rangermc (Crosby)
2017 F-250 Ultimate Lariat CCSB
Yes, I do reset Trip2 (not Trip 1 - totals from purchase). BUT I also just installed a TransferFlow 60 gal tank to replace the 34 gal factory tank. I understood that the factory tank still had about a 5-7 gal reserve when registering empty. The new tank is deeper (removed the skid plate) and longer, SO when registering empty on this first tank full with the original gas gage, I was wanting to calculate the fudge factor and drive it near empty. Hence, the MPG calculation. I do think the average MPG is calculated off the gas gage which is now rather inaccurate. OH WELL, the full use of the first full 60 gal tank will tell the real story. More later when I run through this first tank.
rangermc (Crosby)
2017 F-250 Ultimate Lariat CCSB
Frmr Ford Trans Engr
Joined: Aug 1999
Posts: 24,739
Likes: 2,669
From: SE Florida
The reset is for fuel economy, not trip one or two. The average is over the last 1,000 miles, or since the last time the fuel economy was reset. Resetting the trip odometer does not reset the fuel economy.
New User
Joined: Aug 2017
Posts: 21
Likes: 0
From: Tucson, AZ
Thanks Mark Kovalsky, I will just trust the AVG MPG readout and keep testing the best way to see when the 60 gal tank nears empty. I could always run it dry, carry about 5 gal of diesel in a container and that would tell me exactly how far after the gage registers empty.
rangermc
rangermc
More Turbo
Joined: Mar 2006
Posts: 582
Likes: 2
From: Eads, TN
Thanks Mark Kovalsky, I will just trust the AVG MPG readout and keep testing the best way to see when the 60 gal tank nears empty. I could always run it dry, carry about 5 gal of diesel in a container and that would tell me exactly how far after the gage registers empty.
rangermc
rangermc
New User
Joined: Aug 2017
Posts: 21
Likes: 0
From: Tucson, AZ
Tact, is there a better idea on how to know when a 60 tank will really be empty? Since the new transfer flow 60 gal tank is both longer and deeper with the same fuel gage from the 34 gal tank, the reserve past empty will be significantly larger.
rangermc
rangermc
More Turbo
Joined: Mar 2006
Posts: 582
Likes: 2
From: Eads, TN
I'm not sure what the best way is, but running an engine completely out of fuel makes my skin crawl. I would not be comfortable with what might occur to injectors or fuel pump, but I'd be surprised if those would not be affected.
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Posting Guru
Joined: Jan 2011
Posts: 1,352
Likes: 4
That's funny because my hand calculated is always higher then the display. Guess that theory is wrong.
Frmr Ford Trans Engr
Joined: Aug 1999
Posts: 24,739
Likes: 2,669
From: SE Florida
Why don't you want to reset the fuel economy calculation? While the display is showing fuel economy, press and hold the OK button. That will reset it.
Fleet Mechanic
Joined: Jan 2015
Posts: 1,377
Likes: 294
From: SE Michigan
I record all my fill ups and mileage in Fuel Buddy. For the first four tanks it's calculated MPG for, it's easily been within 1 mpg - probably closer to 1/2 mpg.
My daily commute is about ~55 miles each way. I filled up at my usual station this AM, which is about 1 mile from the expressway (and about 4 miles from home). My work is about 2 miles off the expressway at the other end. So all but ~3 of these miles were on the expressway. I decided to chug along at 65 mph this AM. Too bad it's not always like this:
My daily commute is about ~55 miles each way. I filled up at my usual station this AM, which is about 1 mile from the expressway (and about 4 miles from home). My work is about 2 miles off the expressway at the other end. So all but ~3 of these miles were on the expressway. I decided to chug along at 65 mph this AM. Too bad it's not always like this:
Mountain Pass
Joined: Oct 2017
Posts: 107
Likes: 15
I record all my fill ups and mileage in Fuel Buddy. For the first four tanks it's calculated MPG for, it's easily been within 1 mpg - probably closer to 1/2 mpg.
My daily commute is about ~55 miles each way. I filled up at my usual station this AM, which is about 1 mile from the expressway (and about 4 miles from home). My work is about 2 miles off the expressway at the other end. So all but ~3 of these miles were on the expressway. I decided to chug along at 65 mph this AM. Too bad it's not always like this:
Attachment 248210
My daily commute is about ~55 miles each way. I filled up at my usual station this AM, which is about 1 mile from the expressway (and about 4 miles from home). My work is about 2 miles off the expressway at the other end. So all but ~3 of these miles were on the expressway. I decided to chug along at 65 mph this AM. Too bad it's not always like this:
Attachment 248210
Fleet Mechanic
Joined: Jan 2015
Posts: 1,377
Likes: 294
From: SE Michigan
Yes, but that is was almost exclusively highway. No way that holds up when you mix in some city driving. I'll wait to go through another half dozen tanks (and the engine breaks in more) before really commenting on real world MPGs.
New User
Joined: Aug 2017
Posts: 21
Likes: 0
From: Tucson, AZ
Owners manual for my 2017 F250 6.7l Diesel CCSB says on page 188, "You may want to cycle the ignition from off to on several times after refueling to allow the fuel system to pump the fuel from the tank to the engine. On restarting, cranking time will take a few seconds longer than normal. With Keyless ignition, just start the engine. Crank time will be longer than usual." It also states that when refueling, normally 1.06 gal of fuel is enough to restart, more if on a slope. SO I just read the manual and assumed that Diesels start better than the older models.
Fleet Mechanic
Joined: Jan 2015
Posts: 1,377
Likes: 294
From: SE Michigan
rangermc: Are you referring to restarting a vehicle after it was run out of fuel?
Running an EFI vehicle out of fuel, be it diesel or gas, is much worse than running an old carbureted vehicle out of fuel. It doesn't really have anything to do with fuel type. It has to do with EFI vs carbureated and the high vs. low pressure systems (and all the parts).
Running an EFI vehicle out of fuel, be it diesel or gas, is much worse than running an old carbureted vehicle out of fuel. It doesn't really have anything to do with fuel type. It has to do with EFI vs carbureated and the high vs. low pressure systems (and all the parts).