That is the same way I do it. I just have the XLT and not the Larriot

 

Yeah, factory 4:88's. I'll never expect to get very good mileage with my 10,000 LB tank, but it used to get 13+. Now I'm lucky to get 11. I know it's capable of better than that.

 

Yeah, those are some STEEEEEP gears and a lot of weight. Imagine if you had the V10 you would probably get about 6-8...

 

I was just surprised that after the first click on the pump, that I could still get 4 to 7 more gallons, so I started to fill until I could see it in the fill tube. I have a 27 G tank and have filled it up with 31 G worth of fuel. It's probably the way illinois pumps are set up (more $$ for less). Plus I have to factor in the difference between stock tires and the 35 inch tires that i currently have on. According to the GPS, 7% difference.

I also have every fill-up on a spreadsheet and have MPG for each fill-up and avg since new.

 

I am not sure about that my truck is AT and the hub choice is auto or locked I thought. I leave it in auto year round.

 

If I remember right, which is fewer and farther between anymore, When going 55mph I am at 1625 rpm give or take a little. at 1800 I am closer to 65, more like 63. I have 3.73 gears and 4r100 auto. If you have something different then the numbers are going to differ, someone else will have to chime in.

 

At 1900rpm I am running 65. I try not to go over that.

 

That's about my observation but the speed limit on the interstate here is 70. So everbody is averaging about 75-80. There goes my fuel economy because I cannot be passed like that. By that I mean everybody.

 

Well, now I am going to have to go for a spin tonight and log what RPM for What mileage. Bowdown, can you let us know what drive train you have? I am really curious to find out why you are getting such low mileage. Not doing burnouts at every stop light in town are ya?

 

If he was leaving his truck 4-7 gals shy of full his mileage would be down in the 5 to 6 mpg. wow that really sucks.

 

Okay, just go back from a little drive, recorded the following:
40mph - 1175 rpm
45mph - 1300 rpm
50mph - 1400 rpm
55mph - 1525 rpm
60mph - 1700 rpm
65mph - 1850 rpm
70mph - 2000 rpm
75mph - 2175 rpm
80mph - 2325 rpm
I am sure there is some variance from vehicle to vehicle. I have stock sized tires. My last fillup was on 3/20/06 yeilded 13.036mpg (459.4/35.24). Some highway miles, most of it 2 mile round trip to and from work.

 

It doesn't matter how he fills up his truck (stops when the pump kicks off or fills it to the neck) as long as he does it the same each and every time. Depending on how empty the tank is, the foam factor shouldn't make over 1/2 gal difference in the fill up. Yes, you can pack it on in, but if he is stopping in the same place everytime the mileage should be right.
Joe

 

I have a hard time beliveing this truck is capable of burnouts. The power isn't there. Once I get the CPS I will know if thats part of the issue as well.

I rode the bike into work today.. so no new tests can be done till I get home.

Brisk 30deg ride in .

2000 Auto PSD Crew Cab Dually Shortbox

 

Checked mine as well. All of my numbers were within 50rpms of the same as cangim's numbers. Checked my speed with GPS for accurate readings. My speedo. is off around 10%. My Speedometer vs. GPS
35 showing= 38.6 on gps
45 showing= 49.3 on gps
70 showing= 77.2 on gps
Even stock your truck should at least make you think you could spin the tires. If you are struggling to make power I would think that would kill your mileage.
I hope that the CPS does fix your problem, it would sorta surprise me. Could be a combo of several smaller things.

Tires- Stock and inflated
Boost- Some leaks possible
Fuel- No leaks noted
Turbo- Seems fine
EBPV- OK? (I had one stuck, lots of extra white smoke)
Speedo- OK
Odometer- Accurate
Trans.- Not Slipping
Driving Habits- Better than most
Fuel filter- Good
Air Filter- Good?
Exhaust smoke- No
CPS- Soon to be changed
I am sure I missed some,
Are you sure you station is really selling you a gallon of fuel? If you are using the same one, you might want to carry a 5 gal can with you the next time and check. Also, do you have any sticky fingers around that may be borrowing a can full o ut of your truck every now and then? Man, I hope you find your problem and get off that bike and back in your PSD.


I just became a senior

 

Well I have tried a different station this time around. Guess we can rule that out after this tank. Air filter was new (stock) for all tanks except this one. This one has the Kwik filter.