Recalibrating DIC

JohnDar

Prolifically Gabby Member
Since I'm changing my fuel tank from 34 gallons to 56, I'm wondering if I'll need to have the DIC modified so the fuel economy/usage indications are consistent with the increased capacity. Anybody had this done?
 

Bob&Patty

Founders of SoCal Chapter
John, no and as far as I know the DIC cannot be recalibrated. Whether it will calibate the extra fuel.....probably not. It will only give you readings from the main tank fuel level sensor and miles traveled with the main tank full. I would suggest that when you fill the main tank from the aux tank...make sure the ignition key is OFF.
 

caissiel

Senior Member
I have the scangaugeII in my truck and use it for fuel usage. I have the tank capacity programed in and observe the fuel mileage using it.
Every car or truck I put my SG2 in, I get accurate fuel used and mileage.

This tells me that there are 2 readings that are read by the vehicle OBD2 port. Fuel flow and Tank level.
Fuel flow is very precise but the tank level is in % reading using the float.

Your DIC must be getting the same reading my SG2 and calibrating it to MPG.

The advantage of my SG2 is that I can calibrate it at every tank fill.
 

JohnDar

Prolifically Gabby Member
Just for clarification, I am not adding an auxiliary tank, but replacing the OEM tank (34 gallons) with another midship 56 gallon tank. The original fuel sender unit will be used with the new tank. So, if as you say, the fuel flow is metered and measured, that should remain the same. And if the fuel level is read as a percentage, based on the float position, then the fuel gage should remain "accurate," as well. My concern is with the average mpg and the fuel range display. Guess I'll just wait and see once the tank gets installed (next week, maybe). It's not a big deal, I just kind of like looking at it, from time to time.
 

hoefler

Well-known member
The computer will still calculate off of the original 34 gallon capacity for the level of fuel remaining in the tank. You probably will notice that the miles to empty will not be accurate for the amount of fuel you have. It will appear that you are making fuel, you will drive farther than it indicates.
 

porthole

Retired
Real world here: I had a Titan 52 in my GMC (best thing I did to that truck).

When it was filled up the DTE, distance to empty, would be the miles based on a full tank of 26 gallons. Obviously this is incorrect. But once you get to about half tank it starts to show real numbers. Does it really matter if it stays on 300 miles to empty for a couple of hours?

The fuel gauge was about the sames as the original, as it should be, it is reading a level.

Your DIC fuel economy will remain as accurate as it was. The computer does not know or use the info of a fuel tank to calculate the mileage. The DIC is using the same information the engine computer is using to fire the injectors. Simply put, X number of injectors, firing precise measured amount a fuel under a precise pressure for X amount of time divided by the miles traveled will give you the DIC mileage.

Most of the time I would use the "gallons used" to determine when it was time to get fuel.

You will enjoy the extra freedom, good luck
 

JohnDar

Prolifically Gabby Member
Thanks, Duane. Based on your experience, then, I'll travel something like 250 miles before the DIC starts ticking off the estimated range based on the OEM volume. If the mpg reading is reasonably accurate, I can head calculate my range based on the fuel gage.

Regardless, 56 gallons will get me farther than I plan to drive in one day with the rig on the hitch. If I did get brave or crazy, then I'd be looking for a truck stop before hitting 1/4 tank. I had thought about the 50 gallon in-bed tank, but figured most of the time, I would be hauling around an empty tank or a lot of unnecessary weight. And I'd lose cargo space.
 
Where are you getting the replacement tank? I have been thinking about doing the same thing with my 08 Chevy.
 

porthole

Retired
Where are you getting the replacement tank? I have been thinking about doing the same thing with my 08 Chevy.

My tank was a Titan Tank. http://www.titanfueltanks.com/

At the time I preferred it over the Transfer Flow that John is getting because of size, 52 versus 46 gallons. I also preferred the “plastic” construction over the aluminized steel. No particular reason, just my preference.


Thanks, Duane. Based on your experience, then, I'll travel something like 250 miles before the DIC starts ticking off the estimated range based on the OEM volume. If the mpg reading is reasonably accurate, I can head calculate my range based on the fuel gage.

Regardless, 56 gallons will get me farther than I plan to drive in one day with the rig on the hitch. If I did get brave or crazy, then I'd be looking for a truck stop before hitting 1/4 tank. I had thought about the 50 gallon in-bed tank, but figured most of the time, I would be hauling around an empty tank or a lot of unnecessary weight. And I'd lose cargo space.

John


My tank without the trailer got me from New Jersey to Elkhart without stopping for fuel.
The real advantage though will be you can buy fuel when you want as opposed to when you need.
With mobile internet available now you could search a 100 miles ahead for fuel prices. Or just knowing that you may never have to fuel up with the trailer connected.

I can't believe how many people whine about the DTE stuff on the Truck forums. Geez, if you have 50 gallons and you get 10 mpg towing just get fuel at 400 miles
 

caissiel

Senior Member
I have a 23 Gallon tank in the bed of my truck and it stays there all the time, Its 5 inch thick and 21 inches high and 63 inches wide and fits in front of my in bed tool box that I use when camping. It gives me 61 Gallons capacity and I usually fill where I stop for the night after traveling. If I know my route well I will fuel up when the price is good.

It gives me in access of 600 miles and judge my cheap fillups that way. Its a dirty job filling up in truck stops so the less I do it the better.
 

MC9

Well-known member
A big tank might be a good idea. Then you wouldn't have to do the little dance as often, when the pump shuts off at 75 bucks.
 

hoefler

Well-known member
I have a 75 gal. tank in the bed and a 35 in the truck. I can get between 1,000-1,200 miles on a fill up, depending on driving conditions. It is nice not having to worry bout fuel until you get to your destination. On our 3,300 mile round trip to the Keys and back, I filled up twice on the road.
 

JohnDar

Prolifically Gabby Member
All good info, but as I said, 56 gallons will get ME as far as I think is comfortable to drive (alone) with the rig in a day. And still have a safe reserve to fill back up once I unhitch. Our plans are still to be on our seasonal site most of the warmer Michigan months, so hauling around anymore fuel than that and losing the space for other things I haul from time to time is not necessary.
 
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