I am saying that it will give you a more consistant measurement. The bottom half of my tank goes much quicker according to my dash.

The light comes on when you have 5 gal. remaining so it's not technically empty. I fill it up when the light comes on, note how much I pumped and hit the reset on the odo. Run until the light comes on, fill with the same amount and calculate mileage. Very consistant when using the same amount of fuel as a baseline and same octane gas.

 

Right, so the question is precision and not accuracy across the line. If his measurements are precise (almost all very close) then they are very likely accurate, and definitely as accurate as a full tank.

 

Agreed, but I think this is because of the design of the gauge, not the rate of consumption. I've seen this on most of my vehicles. I think they set the gauge for higher resolution (so to speak) in the lower half where it matters most.

 

give it a try. You'll see a difference.

 

FYI, from what I've seen/read it's more like at 3 gallons. Wouldn't count on 5 gents.


D2 Manual:......

 

you are correct. from Light on to full tank, my trucks takes 22 ish gallons to fill

 

Wait a minute. wait a minute... you aint gonna get off that easy...

How do you intend on doing that!

 

Well.... First I'll either pick up a full set (motor, tranny, t-case) off eBay for about $6k or I'll get lucky and find one in the 2011+ F150's at the junkyard for about $2k out the door. Either way, I'll have to drop the t-case for an Atlas passenger drop or replace the front axle completely for one with a driver side diff. But I think new t-case will be cheaper. Then it's fabricate new mounts and exhaust. Followed by the install of the ECU and wire looms. Next will be mounting the F150 shifter and t-case selector. Followed by swapping out the gas pedals since the ecoboost uses drive by wire. Then I'll have to figure out a plan for the fuel pump (I've read the ecoboost uses a lot higher psi). Next will be mounting an intercooler in front of the radiator after moving it back a few inches due to more room from v8 to v6. From there it will be mostly little stuff like adapting AC lines from old to new, splicing of some wires, and hoping I can splice in old gauge cluster otherwise swapping out for individual gauges.

Oh and new custom length driveshafts. I think that's most everything...

 

As far as measuring mileage on the top half of the tank v. the full tank, I've done both and got the same mpg both ways. The only thing I will say is that when I drive 300+ miles and then fill up when the light comes on, it is usually 300+ miles at once. Not 300+ miles over a variety of conditions, but a straight shot on a highway/freeway.

If i were averaging in city driving then there would be no 16.5!

 

Its a P38 and he is doing a chevy swap, but there is a lot of good information that you can uses, especially keeping the BCU happy.

I'm using it myself for my planning process for my swap, LM7 block, rover sensors. no transfercase or transmission woes....