6.4L Power Stroke Engine and DrivetrainDiscussion of the 6.4L Power Stroke diesel engine and drivetrain in the 2008 Super-Duty trucks. No gas engine discussion allowed except on transmissions and drivetrain that pertain to all models. Please confine discussion of topics in this forum to those items that are specific to the 6.4L Power Stroke engine.
No I didn’t calculate the amount of fuel when I was parked (not sure how I would), I was looking at the MPG on the TDC, it was dropping and I expected the MPG to drop because the truck was not moving (I’ve notice this when stopped at stoplights). It is my thinking that if the truck is not moving, the TDC would only see fuel being used and no miles (MPG = miles divided by the amount of fuel used), which would give me poor MPG till I reset the TDC and give me a average MPG between resets it again. I have kept a complete spreadsheet of my fuel usage, mileage, cost and driving conditions since the truck was new, filling the tank to the brim. I wish the truck had some sort of indication that stayed on during the Regen process, not a 3 second “Cleaning Exhaust Filter” on the TDC. I hope I’m not getting this all wrong, but lessons will continue. This is my first diesel and I bought it to pull my dream trailer up hills and thought in the long run that the fuel cost would be cheaper, but time will tell. I have 3000 miles on it now and had no problems so far and love the truck, just trying to learn all about it. The first trailer outing will be next week. Thanks for the help and interest.
MPD56
__________________ -2008 F-350 CC 4X4 Lariat, SRW, 3.73.
Any color, as long as it's "Black".
Ordered 12/31 - Born 02/11 - Picked up 03/29. -1972 First Ford - 1956 Fairlane - Mint
Rolled it at 100+mph (Teenager, Duh, no one hurt)
Totaled Oct/73 (Over 35 Years ago and still remember that lesson). -First New Ford - 79 Bronco - Ordered Mar/79
150K Miles - I disassembled 2000 and I sent it to three different scrap yards. -1982 - My Sister married a GM Sales Manager (He Retired 2007, "Hello" Ford Super Duty, enough said, LOL). -2003 - ZRX1200 (Some say "Mid Life", LOL). -2008 - Jayco 313RKS 5th (The kids won't move out of the house).
The reason I asked is because the truck burns a lot of diesel while high idling during regen. I have no doubt it increased in mpg after regen, but you have to include the amount of fuel burned (i.e., your money burned) while it was in regen. Whether covering miles or not, it's still burning your diesel. I just wonder if the mpgs post regen are increased enough to offset the diesel burned during the 20min spent idling at 1500rpm.
The DPF does its job by getting hot. Drive'n around town does not get the DPF hot enough for the DPF to burn off particulet by itself. When drive'n a speeds of 65 or more the DPF can get itself up to a temp of 1500 more by itself without extra fuel. If i remember correctly the DPF gets up to 2300 degrees during regeneration. Once the DPF is cleaned you get higher flow and better mileage. I did not like my truck to regen because of fuel usage. I did my best to keep it from doing a regen, I wanted it to clean itself with extra fuel. However, after about 500 miles it go into a failsafe regen, I had hard time keeping from do a failsafe regen. As far as how much soot it takes to cause regen or the amount of back pressure, I don't know.
Thanks for the replies and information. I love learning about my first diesel and I have lots to learn. This is a great forum.
MPD56
__________________ -2008 F-350 CC 4X4 Lariat, SRW, 3.73.
Any color, as long as it's "Black".
Ordered 12/31 - Born 02/11 - Picked up 03/29. -1972 First Ford - 1956 Fairlane - Mint
Rolled it at 100+mph (Teenager, Duh, no one hurt)
Totaled Oct/73 (Over 35 Years ago and still remember that lesson). -First New Ford - 79 Bronco - Ordered Mar/79
150K Miles - I disassembled 2000 and I sent it to three different scrap yards. -1982 - My Sister married a GM Sales Manager (He Retired 2007, "Hello" Ford Super Duty, enough said, LOL). -2003 - ZRX1200 (Some say "Mid Life", LOL). -2008 - Jayco 313RKS 5th (The kids won't move out of the house).
My truck has about 1400 miles on it. Yesterday I noticed the "cleaning exhaust filter message" for the first time. I was on the expressway with the cruise set at 62. Dash was reading 13.3 and then began dropping to 12.5. I was about five miles from my destination. I never saw anything that said the regen was complete (I think the manual says it will tell when it's done too).
On the trip home (about 25 miles) with the cruise set at 62 again the dash got up to 14.8 and it was still climbing until I got off the expressway. It dropped to 14.7 and was back to 14.8 by the time I got home. So far this is the highest reading I've ever seen.
My truck has a 3.73 rear end and I generally drive it real easy - RPMs under 2k and try to keep the boost below 10 PSI unless I'm going up a hill. Pretty soon I think I'll horse it to see what that beast will do though.
__________________
Bill
2008 F350 FX4 CC PSD SB
Most everything but Nav & DVD
Line-X bedliner
BakFlip tonneau cover
Reese 5th wheel hitch
My truck has about 1400 miles on it. Yesterday I noticed the "cleaning exhaust filter message" for the first time. I was on the expressway with the cruise set at 62. Dash was reading 13.3 and then began dropping to 12.5. I was about five miles from my destination. I never saw anything that said the regen was complete (I think the manual says it will tell when it's done too).
On the trip home (about 25 miles) with the cruise set at 62 again the dash got up to 14.8 and it was still climbing until I got off the expressway. It dropped to 14.7 and was back to 14.8 by the time I got home. So far this is the highest reading I've ever seen.
My truck has a 3.73 rear end and I generally drive it real easy - RPMs under 2k and try to keep the boost below 10 PSI unless I'm going up a hill. Pretty soon I think I'll horse it to see what that beast will do though.
Try getting your speed up to 63 to 68, I have found my best mileage at those speed ranges. I seem to think it has to something to do the power to weight ratio and high gearing. As it breaks in you get better mileage. Change that factory oil out at 3,000 miles, your mileage will go up even more.
Im glad to see some of you are getting good milage if you call 14-16 good, i seen 16 on the dash once since i bought the truck, took the truck back when it dropped to a consistant 11mpg, ford had it for a week, got the truck back and they said there was nothing wrong with it, got 15mpg after that but has dropped back to 11 since (i dont drive any short trips, usually 420 miles one way and then drive back 12-20 days later) and your right the best milage seems to be around that 70 mph range, I hooked up to my fifth wheel last weekend (14000lbs) and got 5-6mpg, my 2007 pulling the same trailer was getting 12-14mpg (too bad the truck was stolen), both 1 tons, both with the same rearends. I'm sure hopin Ford figures out something soon !
If anyone has any suggestions, im open to options, love the truck but cant stand the milage.
Especially when diesel is averaging 1.37-1.45/ltr (5.17-5.48/US gal)
Did you calculated the amount of fuel burned while your truck was in regen while parked, or did you just calculate your mpg while on the road?
I read on one of the forums that a 6.4 owner filled up then drove off and his truck went into regen. He sat at the side of the road until it stopped the regen (1/2 hour?) then went back and topped off the tank and it took 4 gallons. There is no way you get better milage because of a regen. I set the cruise at 65 mph unloaded) and watch the message center go from 9.5 to 13 mpg on my trips and get off the freeway and in drops right back down to 9.5. I have never gotten double digits with my truck. The "sweat spot" with 4.88s is 55 mph and I can't drive that slow!
__________________
2008 F450 Dark Shadow Gray Lariat "Pick Up", Torqueshift, 4.88 LS, 4x4 Off Road, Shift On The Fly, Traction Control, Back Up Sensor, Tail Gate Step (no handle), Upfitter Switches, Power Rear Window,PTO, Supplemental Heater, Dual Alts, Adj Pedals, Sirius, Tow Command, Captains Chairs, LineX, Smoke Cab Lenses, and Billet Badges
Better mileage during a regen, absolutely not, but better mileage as a result of a regen, yes. To truly validate that test, it should be run again at idle without the truck in regen to see how much fuel it burns while regularly idling. Seems to me Ford claims that an hour of idling is equivalent to 30 miles driven. Regardless, 4 gallons (dam near 16 liters) is a hell of a lot of fuel for 30 minutes of idle! But we're saving the planet by sticking these filters on ... rubbish.
__________________
2003 350 Lariat FX4 Short Box 6.0L *SOLD*
2008 FX4 F350 6.4L Dually Long Box, Black on Black PICTURES
2007 Keystone Raptor 3712TS PICTURES
It got a WHOOPING 16.5 MPG ... I got 17.8 MPG on the way home...
Is it possible that in Regen the system "Cleaned" itself which in turn gave me an increase in MPG?
Lost of things are possible.
Which way was the wind blowing? Only a 4 mi/hr headwind (5% of your speed) outbound and a 4 mi/hr tailwind returning could account for your 8% fuel economy change. Was traffic a lot heavier on the way back? Even without deliberately drafting, a large number of vehicles all moving the same direction does create its own local wind, reducing the headwind you'd encounter were there only a few, widely-spaced vehicles on the road.
A favorable sun angle on the return trip might have resulted in a lot lighter air conditioner duty cycle.
Just to mention a few of the many variables.
__________________
-
Douglas Campbell [drcampbell ot engineer dat kahm]
November 5, 2008: The fat lady sang. Back to actually working for a living.
1986 Isuzu P'up, 177,673.8 miles. Hella headlights, (highly recommended) DOT C-2 back end. (also recommended) R-12 air conditioner converted to R-406a. 4.1:1 rear axle converted to 3.4:1.
9/22/2007, age 21: Still running well when reluctantly sent away for reincarnation, due to body & frame rust.
I've noticed lately that the my "cleaning exhaust filter" message stays on until the regen is done (averages 15-20 minutes). Does anyone else's "cleaning exhaust filter" message stay on during the regen process or is my truck "special"?
__________________
2008 F-450 "Lariat" Fully Loaded (Picked Up 01/26/08)
2008 Ford "Focus" (To Help Out With My Diesel Guzzling F-450) "Did I Say I Love My F-450 Though"
2007 Raptor Toyhauler 3612DS http://i181.photobucket.com/albums/x...Picture221.jpg
I've noticed lately that the my "cleaning exhaust filter" message stays on until the regen is done (averages 15-20 minutes). Does anyone else's "cleaning exhaust filter" message stay on during the regen process or is my truck "special"?
I've noticed lately that the my "cleaning exhaust filter" message stays on until the regen is done (averages 15-20 minutes). Does anyone else's "cleaning exhaust filter" message stay on during the regen process or is my truck "special"?
I have a job 3, 2008, f350 4x4, lariat, crew cab, w/ 3.73 LS, and a bed cover. while running errands in town, i noticed the "cleaning exhaust filter" message for the first time. it displayed for only about 5 seconds then went off. this happened at about 490 miles. i went into the store and when i got back in the truck and started it up, the "cleaning exhuast filter" message came on again for about 5 seconds then went off.
since i was done with my errands, i jumped on rt. 66 and went for an approx 40 mile ride home between 55-65mph. funny thing is, the mpg display went up from when i last saw the "cleaning exhuast filter" message. if this truck went into "regeneration," i sure didn't notice it.
i know have 623 miles on the truck with 12.9 mpg on the display with about 70% highway (under 2000 rpms and keeping the boost at about 10) and 30% in town and screwing around in low gears 4x4'ing.......... mpg's haven't been that bad.
I've noticed lately that the my "cleaning exhaust filter" message stays on until the regen is done (averages 15-20 minutes). Does anyone else's "cleaning exhaust filter" message stay on during the regen process or is my truck "special"?
The message in my truck lasted a few seconds. Then it was gone. Your truck must be special. :-)
__________________
Bill
2008 F350 FX4 CC PSD SB
Most everything but Nav & DVD
Line-X bedliner
BakFlip tonneau cover
Reese 5th wheel hitch
Which way was the wind blowing? Only a 4 mi/hr headwind (5% of your speed) outbound and a 4 mi/hr tailwind returning could account for your 8% fuel economy change. Was traffic a lot heavier on the way back? Even without deliberately drafting, a large number of vehicles all moving the same direction does create its own local wind, reducing the headwind you'd encounter were there only a few, widely-spaced vehicles on the road.
A favorable sun angle on the return trip might have resulted in a lot lighter air conditioner duty cycle.
Just to mention a few of the many variables.
My trip was done with the same traffic both ways (next to none) and no AC use. And after mixed use driving today the computer still showed 14.7. We'll see what the tank hand calcs out when it's time for a fill up. I have a car to drive as well so it will be awhile.
Granted, it's a thirsty vehicle. And I know it's nothing compared to what the pre-DPF trucks got for mileage. But compared to a gas engine, for the power the truck has, it's not too bad. My former F150, driven a little harder, would do no better than 17 MPG. It had the 5.4 V8, was a SuperCab vs. a CrewCab and didn't have anywhere near the power obviously.
Now if someone could explain why diesel costs $1.00 a gallon more than gas, I'd love to hear it...
__________________
Bill
2008 F350 FX4 CC PSD SB
Most everything but Nav & DVD
Line-X bedliner
BakFlip tonneau cover
Reese 5th wheel hitch
-2008 F-350 CC 4X4 Lariat, SRW, 3.73.
