2001-early 2004 LB7 Duramax Fuel Economy Poll

[DRINKDIESEL]

Getting an easy 20mpg highway. Up to 23 on longer trips with '04 EC LB 4x4 SRW and the Juice with A2 set on milage(#1). Also installed a K&N air filter and modified the stock air box which helped a bit. I'll keep working on it.

[DmaxMaverick]

Getting an easy 20mpg highway. Up to 23 on longer trips with '04 EC LB 4x4 SRW and the Juice with A2 set on milage(#1). Also installed a K&N air filter and modified the stock air box which helped a bit. I'll keep working on it.

Just curious.
Is that mileage from the DIC, or are you calculating manually?

[DRINKDIESEL]

From the DIC. I was getting ~17 before the mods on the DIC.
I'll calculate it out on the next fill up.

[DmaxMaverick]

The reason I asked, is when using a power adder, the DIC tends to become quite optimistic. Usually, a very disapointing reality is discovered once the mileage is calculated manually. This inaccuracy is normal and consistent with the operation of the module/programmer. Problem is, the manufacturers don't disclose this in their literature. Most folks just go on thinking the mod has given them great mileage.

Please get back to us with your results. Some folks reported the DIC mileage was still accurate with a module installed. If one can do it, they all can. There's no reason to not have the DIC calibrated, if it's possible. In either case, we should either have a calibrated DIC, or a formula to determine actual mileage from the DIC info.

[DRINKDIESEL]

The reason I asked, is when using a power adder, the DIC tends to become quite optimistic. Usually, a very disapointing reality is discovered once the mileage is calculated manually. This inaccuracy is normal and consistent with the operation of the module/programmer. Problem is, the manufacturers don't disclose this in their literature. Most folks just go on thinking the mod has given them great mileage.

Please get back to us with your results. Some folks reported the DIC mileage was still accurate with a module installed. If one can do it, they all can. There's no reason to not have the DIC calibrated, if it's possible. In either case, we should either have a calibrated DIC, or a formula to determine actual mileage from the DIC info.

Gimme a couple of weeks. I'll reset the DIC at the next fill up and compare.
You've got me worried now.
K

[DRINKDIESEL]

The reason I asked, is when using a power adder, the DIC tends to become quite optimistic. Usually, a very disapointing reality is discovered once the mileage is calculated manually. This inaccuracy is normal and consistent with the operation of the module/programmer. Problem is, the manufacturers don't disclose this in their literature. Most folks just go on thinking the mod has given them great mileage.

Please get back to us with your results. Some folks reported the DIC mileage was still accurate with a module installed. If one can do it, they all can. There's no reason to not have the DIC calibrated, if it's possible. In either case, we should either have a calibrated DIC, or a formula to determine actual mileage from the DIC info.

Sorry it took so long to get back to you. Things are hoppin' at the shop here.
Here's the results of the DIC to actual.
513.8 miles-crappy single lane small town type
102.0 litres which equals 27.01 US gallons
19.02 MPG Calculated
19.4 MPG on DIC
A slight difference between DIC and actual, but not much.
I ran on level 1 (mileage) most of the time with the A2. I'll see what the DIC says when I pull my 27' 5th wheel with 5 guys and all their gear to the IHRA Canadian Nationals this weekend.
K

[DmaxMaverick]

Thanks for the comeback.

I don't consider less than 1/2 MPG outside of the normal variation, with or without mod's. If you are in fact getting accurate mileage displayed by your DIC, we need to find out why. Like I said, if it can be had by one, it can be had by all. It is interesting that some folks with the same truck and mod, get different results, in regards to the DIC.

What other upgrades do you have on your truck? Tire size, etc.

[JohnC]

Like I said, if it can be had by one, it can be had by all. It is interesting that some folks with the same truck and mod, get different results, in regards to the DIC.

I'd expect it has to do with how far from optimal the injector flow rates are. The PCM only knows how much it is commanding, not how much is actually delivered.

My DIC mileage is always within 1 or 2 tenths of calculated mileage. Same for fuel used.