6.4 gas tank useful capacity

[Crusty old shellback]

So I took a trip this weekend, 875 miles.

For the run home, I wound up doing a 450ish mile trip without fueling back up. A few things I noted.

15.1 MPG on the lie o meter

When the range miles display hits 50 miles left, the fuel pump light come on saying you need to refill.

When the range miles displays 10 miles left, it then turns to low instead of counting down to 0.

I still drove at least 10 more miles before I got to my gas station.
Filled up this morning with almost 28 gallons of gas. So if the tank is indeed a 32 gallon tank, then it has at least a 4 gallon reserve after it says you are out of gas.

On a side note, pump stopped at $150. and I had to start it back up to finish filling, $173 dollars total at $6.02 a gal.

 

[jdefoe0424]

With aftermarket tires I'm not surprised that your indicated MPG is inaccurate.
Yes, there is quite a bit of reserve (in terms of volume) but I've found that the angle the truck is sitting at when fueling can make a big difference in how much you get in too.

 

[sanda]

When I'm low I have to re-start the pump three times to fill my 50 gallon tank. BS!

 

[Crusty old shellback]

With aftermarket tires I'm not surprised that your indicated MPG is inaccurate.
Yes, there is quite a bit of reserve (in terms of volume) but I've found that the angle the truck is sitting at when fueling can make a big difference in how much you get in too.

I've corrected for tire size with a Apfaobd.
The complete trip was 870 miles. I did not reset the MPG meter till the end of the trip. So total for the trip came up 15.1 MPG. I only guestemated at the mileage for the last fill up and came up 15.7 MPG for the last tank/second half of the trip, which was about 450 miles. And a out 200 miles of it was below 50 MPH. Was on highway 1 from Monterrey to San Louis Obisbo on the coast.

 

[jadmt]

i have put close to 30 gallons in before and several times have put ~28 gallons in. When I fill up I do it the same each time. let the pump click off wait 20 seconds or so and wait for it to click off a second time. Kind of like the TFL guys do it. I used to keep adding fuel until it was in the neck of the fill tube but learned that could screw up your charcoal canister. One of these days I will run it out and see what the real useful capacity is, just haven't had the balls to do it yet lol.

 

[DevilDodge]

I ran mine out. My fuel level sensor has been MIA since 110000 miles.

My son and I where heading out in the morning. The night before I knew I needed gas. Was going to get it on an errand we ran...but forgot on the way back home. Got up, went out started the truck(oblivious to last nights need for gas) walked back in the house to get my son...issue putting his shoes on.

Go out the truck is off.

You dumb **** I tell my self.

Take our Jeep and go get 5 gallons of gas.

Drive the .56 miles to the Gas station. Put 27.5 gallon in the truck. Did the TFL fill up mentiones above.

 

[DevilDodge]

You need to remember how long our tanks are and that the fuel pump is at the front. The reason for the almost 4 gallon reserve...so people do not run out of gas on a hill, starving the fuel pump.

 

[Crusty old shellback]

They haven't upgraded to a mat yet like all the aftermarket has?

 

[DevilDodge]

They haven't upgraded to a mat yet like all the aftermarket has?

Not that I know of. First i heard of this. Hmmm. Wonder if they make a replacement that way.

 

[@JC]

So I took a trip this weekend, 875 miles.

For the run home, I wound up doing a 450ish mile trip without fueling back up. A few things I noted.

15.1 MPG on the lie o meter

When the range miles display hits 50 miles left, the fuel pump light come on saying you need to refill.

When the range miles displays 10 miles left, it then turns to low instead of counting down to 0.

I still drove at least 10 more miles before I got to my gas station.
Filled up this morning with almost 28 gallons of gas. So if the tank is indeed a 32 gallon tank, then it has at least a 4 gallon reserve after it says you are out of gas.

On a side note, pump stopped at $150. and I had to start it back up to finish filling, $173 dollars total at $6.02 a gal.

It's a 31 gallon tank not 32. On the way back from the cabin this weekend I ran it about 7 miles in to low, I put 28.2 gallons back in after waiting 20 secs or so and clicking the handle twice. My MPGs were around 11.2 with the ACC set to 84 on the interstate. Let's be honest here, there's no possible way you were getting 15+MPG in a PW with 35s.

 

[Crusty old shellback]

Holley makes them. There are other brands as well.
Summit racing carries them. Jegs I'm sure does as well.

It's a 31 gallon tank not 32. On the way back from the cabin this weekend I ran it about 7 miles in to low, I put 28.2 gallons back in after waiting 20 secs or so and clicking the handle twice. My MPGs were around 11.2 with the ACC set to 84 on the interstate. Let's be honest here, there's no possible way you were getting 15+MPG in a PW with 35s.

Was doing a lot of 45 MPH driving on the coast highway on the way home, about 200 miles worth.
Kept it under 75 for most of the rest of the drive on the highway.

Lie O meter showed 15.1 MPG for the whole trip. I filled up for the trip and reset it then. Never reset it until I filled up after the total trip, 875 miles worth.

Hand calculating for the second half of the trip with a lot of 45 MPH driving came up to 15.7 MPG

And yea, I normally see mid 13's for my trips. Just this one was a lot slower. Best I've ever seen in the 18K miles I now have on the truck.

I've noticed that anything over 75 MPH and the MPG basically stays the same. Anything 70 MPH and lower and it will go up.

And from DevilDodge's post, looks like he put 32.5G in his after running it out of gas.

 

[DevilDodge]

 

[jadmt]

View attachment 40006

my 2020 build sheet says 31 gallons.

 

[jadmt]

It's a 31 gallon tank not 32. On the way back from the cabin this weekend I ran it about 7 miles in to low, I put 28.2 gallons back in after waiting 20 secs or so and clicking the handle twice. My MPGs were around 11.2 with the ACC set to 84 on the interstate. Let's be honest here, there's no possible way you were getting 15+MPG in a PW with 35s.

why not?

 

[Jsboening]

I’ll be happy as heck if my 6.4 megacab gets 16mpg. Supposed to be in shipping right now. My 1500 5.7 3.92’s might get 17-18 on a good day.

 

[H3LZSN1P3R]

It's a 31 gallon tank not 32. On the way back from the cabin this weekend I ran it about 7 miles in to low, I put 28.2 gallons back in after waiting 20 secs or so and clicking the handle twice. My MPGs were around 11.2 with the ACC set to 84 on the interstate. Let's be honest here, there's no possible way you were getting 15+MPG in a PW with 35s.

Its all in how you drive…

 

[Gondul]

i have put close to 30 gallons in before and several times have put ~28 gallons in. When I fill up I do it the same each time. let the pump click off wait 20 seconds or so and wait for it to click off a second time. Kind of like the TFL guys do it. I used to keep adding fuel until it was in the neck of the fill tube but learned that could screw up your charcoal canister. One of these days I will run it out and see what the real useful capacity is, just haven't had the balls to do it yet lol.

Did it last year...

Ran the truck until the "LOW" indicator showed up on the DTE Dial.
Drove another 40-ish miles before I ran out of gas... there was no sputtering or warning, it simple stopped running.
Waited 30 seconds or so and then hit the 'Start' button again... all it did was crank and did not fire up.

I put in 5 gallons out of the can I brought with me for this purpose and the truck started right up.
It was then a 2 mile drive to the gas station where I added 25.88 gallons of gas.

 

[jadmt]

Did it last year...

Ran the truck until the "LOW" indicator showed up on the DTE Dial.
Drove another 40-ish miles before I ran out of gas... there was no sputtering or warning, it simple stopped running.
Waited 30 seconds or so and then hit the 'Start' button again... all it did was crank and did not fire up.

I put in 5 gallons out of the can I brought with me for this purpose and the truck started right up.
It was then a 2 mile drive to the gas station where I added 25.88 gallons of gas.

So almost the full 31 good to know

 

[Pronto]

Mine is 27-28 when I take the DTE down to where it would be zero. Every setting in AlfaOBD that I found that could change that was already set to the minimums.

 

[Pronto]

I’ll be happy as heck if my 6.4 megacab gets 16mpg. Supposed to be in shipping right now. My 1500 5.7 3.92’s might get 17-18 on a good day.

I'd think I was driving a Prius if my 6.4 megacab got 16 mpg.