Larger fuel tank

[Shokyle1]

I will be installing a 56 gallon diesel tank in my in-laws 2019 gmc 2500. Has anyone done this. My question is how did you get the miles to empty to work? The dealer says they cannot program the tank size in the ecm like the ford dealer can.

[CAG]

Is this a Titan replacement for the original or an in bed tank?



I replaced the puny 26 gal tank in my 04 with a 52 gal Titan. The only way to reprogram is with something like EFI Live, which is what I had done. I also had the DIC programed for the larger tires I had on. Those who previously programmed with EFI are a little cautious because of the Feds coming down on those who were doing deletes. So finding someone might take some research.

[Shokyle1]

It is the replacement tank. How did you find someone with live wire just call around or are dealers listed on their web site?

[CAG]

There may be other options but I don’t have a Duramax any longer so am away from it but you might call Kennedy Diesel for some advice. He is by far the best in that field. Kennedydiesel.com is the place to start. His site still lists EFI Live tunes.

[Shokyle1]

Awesome thanks for your help.

[Lake Huron]

Why would you need to reprogram it? The truck uses the fuel level in the tank to determine your DTE, along with the engine RPM, engine load, what gear the transmission is in, what % the throttle is at, speed, etc...
I'd bet if you install that new tank, it's not gonna read a 50mi DTE when you have a half tank of fuel left.

[Shokyle1]

All the info I have read says your mpg and gallons used is correct. And because you use the original sender the fuel gauge still works. But because the dte is a calculation on mpg based off the original tank size it will be incorrect.

[edatlanta]

I made this switch to the 52 gal Titan tank replacing the OEM 26 gallon one 13 years ago. The original sending unit is still working fine even after 13 years.

Since we are talking double the original tank size, it is pretty easy to multiply DTE by 2 to see what the distance is with the larger tank. The fuel used between fill ups will be correct regardless of tank size as long as you reset it unless yours is automatic. The only other item that is different with the new tank is when the low fuel light comes on. Before the switch to the larger tank I would have approx 5 gallons of fuel remaining, after the switch there is approx 10 gallons left.

Minors issues and not worth trying to reprogram the system in my opinion. I see 200 miles left to empty and I think 400. Even my old brain can do that.

[CAG]

However his was not a simple doubling of tank size and with EFI you can make other adjustments.

If it is like my 14 it was a 36 gal tank.

[Shokyle1]

Originally Posted by CAG

However his was not a simple doubling of tank size and with EFI you can make other adjustments.

If it is like my 14 it was a 36 gal tank.

Yes it 36 my in-laws want their dte to work correctly.

[CAG]

Originally Posted by Shokyle1

Yes it 36 my in-laws want their dte to work correctly.

Yeah, me too. Call me anal or whatever but going down the road guessing at my speed or the amount of fuel left is not something I was interested in doing and when it came time to sell it I did not want to have to explain all of that to the new owner.



Interestingly, once I had the 52 gal tank in I could go from Phoenix to Guymon OK and not have to fuel (truck only of course). My bladder would not make that far. I probably could have gone further since about 1100 miles was a full tank. My DIC however would only read 999, until it got below that amount of fuel. The LB7 was the last of the no emissions Duramax. My highway MPG was up around 22-24.



There are a number of legal tunes that can be done with EFI. Many did tow/haul tunes and there are tunes that can be done to increase torque and HP beyond the limits of the Allison which is hard to believe considering that transmission. That engine is a beast but in order to unleash the beast work has to be done to the rest of the drive train.

[Seann45]

I have one and its a little out till you get near empty... Just make sure you index the fuel level gauge properly... The guy (idiot) I hired to install mine did not do that and the float hung up on the side of the tank..

[Shokyle1]

I will definitely watch the orientation of the sender when I transfer it. I got a 60 gallon tank for Christmas for my superduty I can program my tank size my self. Just quite frustrating that a dealer cannot even do it for the gm products. But I will figure a way to have it done.