Fuel Consumption Info on DIC

[Ocean Guy]

How accurate is the fuel consumption information displayed on the driver information center (DIC)? I keep an eye on the Fuel Used number on the DIC and compare it with the amount I pumped in. I have noticed that pumped in amount is a gallon or more than the fuel used number. I always buy the gas from the same station, wondering if they fiddled the pumps.

[PaulieK]

My DIC is a little funny also, For instance I can fill it up and get lets say 314 miles range. Run it untill almost empty, fill her up and only get a range of 280 miles. Also sometimes I will use lets say 20.4 gallons from full and pump in 21.5 or 19. whatever before the pump turns off. So it is my opinion that it is only a guide because if I used 20.4 gallons it should only take 20.4 not 21 and change gallons.

[team3-8]

On my 2003 mine has been pretty accurate. If it says I used 19.7 gals when I fill up and let the pump run till it clicks, it will usually be within .1 or so. I was really suprised. If I top it off the next time I get gas this is when it is off. All in all mine works good. I was surprised.

[dewfpo]

DIC says 13.1mpg

 

Actual 12.43 mpg

 

Off by -5.4%

 

DEWFPO

[Buggle_96]

DIC says 13.1mpg

 

Actual 12.43 mpg

 

Off by -5.4%

 

DEWFPO

 

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What method are you using to know your actual fuel consummed?

[asilverblazer]

Time spent idelling at lights warming it up in the morning can alter the "Miles" per gallon, because no miles are being traveled.

[GM-Tech]

I believe the calculated mileage on the DIC is very accurate. The computer knows exactly how much fuel is being delivered when it pulses 8 injectors for 3.24 milliseconds, for example.

 

I think it's much more likely that when you fill up, you're not getting the fuel to precisely the same level each and every time.

[dewfpo]

DIC says 13.1mpg

 

Actual 12.43 mpg

 

Off by -5.4%

 

DEWFPO

 

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What method are you using to know your actual fuel consummed?

 

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Actual miles on odometer divided by actual gallons used at the pump ( 0.000 accuracy ). I keep a spreadsheet of every fillup since this is a business truck.

 

DEWFPO

[6Burgh]

Mine isn't very accurate. I get 14-16 and it says I get 16-18.

[Ocean Guy]

I always top the tank to the neck (is it good or bad ??), and always reset the DIC before starting the engine. I would understand if the actual fuel is sometimes less and sometimes more than the DIC, however, in my case, DIC is always lower than the actual gallons.

 

Hey Paluie, how are you? This is Ken from Quadrasteer Club.

[PaulieK]

I always top the tank to the neck (is it good or bad  ??), and always reset the DIC before starting the engine. I would understand if the actual fuel is sometimes less and sometimes more than the DIC, however, in my case, DIC is always lower than the actual gallons.

 

Hey Paluie, how are you? This is Ken from Quadrasteer Club. 

 

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Hey Ken!!! Whats up bud? I cant believe how dead the QS Club site is lately. Did You get your decals??

[lrymal]

I believe the calculated mileage on the DIC is very accurate.  The computer knows exactly how much fuel is being delivered when it pulses 8 injectors for 3.24 milliseconds, for example...

 

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I totally agree with this. And the computer is logging all of this and comparing against the miles mounting. These miles mounting can vary by tire pressure, tire size, tire temperature. If GM would marry On-STAR's GPS as part of the data coming in, then the accuracy would really be dead-on.

 

But, the current scheme is right on target. I have held off on commenting until I did a couple of tanks through my '03 and '05 Z71s. The tires are factory size (VERY important for this comparison!) Because of the weather, we've been having to move a lot of hay and other stuff around on the farm. Really a good opportunity to check the DIC mileage. Some mornings included warm tires, 20 degree cold tires. Lots of driving through pasture mud and, later, an hour on the freeway. Comparing the math with the DIC, I'm averaging about 5% error. That ain't bad at all.

[Tor Diesel]

I have found it to be very accurate also. Accurate enough to show an instant change in MPG when my wife drives the Yukon. She's a lot heavier on the pedal than I am. My other car is a 94 4Runner with the puny 3.0 v6 so I'm used to taking my time to get up to speed. Her other car is a VW TDi which is surprisingly fast. She likes to hear the turbo wind up so she's heavier on the pedal.