I meant your overall average. The regen process will hurt your overall MPG's, so the fewer times it goes into regen, the better your MPG's will be.

 

Ive been reseting alot lately and screwin off. So i couldnt give u a accurate right now. I did just catch a regen cycle tho, during the cycle i was averaging 9.6mpg at a constant 40mph. its like GRRRRR. And it lasted for like 10min than it started creeping upto high 12's.

 

radzer0,
try filling the tank,hit your reset button on your odometer,run the tank down around 1/8 or so,then fill up the tank.
write down the miles from the odo,and the gallons it took to fill the tank.
this will actually tell you what your MPG was for that tank.
(the more tanks you do this with,the more accurate your actual average fuel mileage will be.don't be concerned with peaks and lows of the built in meter.)
we would appreciate it if you wouldn't mind.thanks.

 

Next time i see a decent pump (one that doesnt spray all over the side of the truck) ill fill up till it clicks. When i get a fuel light ill fill it up and write down milage and how much it took to the first click at the same gas station. Being i dont have a female right now as of today it might be a week or 2 for me to go thru a tank lol

 

Although they maybe out, my car is 10%-15% out, I bet milage will still increase over the 6.4 powerstroke, with out a doubt the lie-meter will read higher then actual results but I still say the 6.4 will do better.

The shop I work at tracks fuel usage through an automated system and our 6.4 f-450's are pulling off 4-6mpg all cities. Thats brutal.

 

I've skimmed over this post.

1st, diesil engines do not create manifold vacume under normal operation.

The benifit of a diesil is the ability to run fuel ratios anywhere from 5:1 to 100:1. That enables a person to create big horsepower numbers and also obtain great fuel economy. The abilty to have an engine to obtain good fuel economy is to improve engine effeciency which can be done in the air intake system, exhaust side systems even in the lubrication and cooling systems and of corse fuel system. This would be typical for your pre-emmision engines.

With todays emeissions that kinda throws the whole concept out the window and too many factors play with emmisions now.

Big factors effecting MPG on a truck is mainaining peak torque at cruising speed. even though the engine may not be creating the peak torque that usually where the engine is effencient at.

Weight, the new Super duties weighs more today then my 97 f250hd PSD, bigger tires, more rotating mass. yadda yadda yadda so right their its even harder to obtain better fuel milage ontop of emmisions with the added weight and horsepower.

 

Do you think anyone is babying those trucks tho?

 

To be honest, my LOM is as often over by 1-1.5 MPG as it is under. I can't speak with any certainty about the new 6.7L, but I can say with conviction that the Lie-o-Meter on the 6.4L trucks is NOT skewed to read above the true figure.

 

The trip computer relies on the speedo/odometer. Which from what I understand can be +/- 10% inaccurate by law. If you hand calculate it, you're also likely relying on the odometer. So IF you used exactly 25 gallons of fuel, and your odometer says you did exactly 400 miles. You hand calculate it at 16mpg, but you really could have gone anywhere between 364-440 miles. So your 16mpg could be really as low as 14.56 and as high as 17.6. It's also pretty tough to measure that you have used exactly 25 gallons too. So when I measure my fuel economy, I have to trust that my speedo is accurate and that when I fill the tank back to the click, that I have replaced exactly what I used since I last filled up to the click. So neither your own manual test or the trip computer are going to be scientific. Having said that, I think people are going to see the fuel economy advantage with the 6.7 over the previous two engines.

 

Remember, we arent required to have "certified" speed-o's neither. Only police package cars. So its posable its 1-3mph off.

 

Not a chance. The "click" operates on back pressure. Which will vary depending on weather, temp, etc.; how fast the pump is running; how far down the filler neck you stick the nozzle, etc., etc. Also, it will vary pump to pump.

 

I think they only way to can do even close is from click to click, but then add fuel to roughly the same spot on the filler neck that you can see and verify, otherwise click to click will be in the ball park only.

 

I know the click varys but thats why i was figuing the same exact pump.

 

While filling to the click may not be an exact science, I will say that if you visit the same station and fill from the same pump each time, you will get pretty consistent results. I've filled to the click on my truck for the last 328,000 miles and gotten some very consistent results. Sure you get a stray reading every once in a while, but I'd trust it more than the lie-o-meter.

The earlier comment about the speedo / odo being off is valid also, but that's pretty easy to check with a GPS.

 

The ECU knows precisely how many shots of fuel have been delivered to engine, and precisely how much fuel is in each shot.

Multiply one times the other and divide by the miles from the odo and you get MPGs.

I really find it difficult to believe that "listening for the click" is more accurate than the ECU.

If the mileage meter is off, the most likely cause is the odo input. Although variations is fuel density and BTU content could throw the ECU off.