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Discussion Starter #1
Is there a way to adjust the fuel usage display on the DIC that tells you what your instantaneous fuel and average fuel is for estimated range?
 

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Not quite sure I understand your question.

The DIC has a page for both instant and average fuel usage, and the range does adjust based on how you are driving.


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Not quite sure I understand your question.

The DIC has a page for both instant and average fuel usage, and the range does adjust based on how you are driving.


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There is a 20% difference of fuel used for MPG than when looking at average MPG of the DIC.

For example, with my mods below, I used 17.1 mpg cruising with an "average" speed of 66mph and cruise set at 81 (difference is because even on interstate you have to slow down for stretches of construction or slower traffic which pulls down the "average" speed). Over the same distance the DIC said my "average" fuel economy was 18.6 mpg.

It only matters because I calibrated gauges and instruments as one of my duties in the Navy.

I'd like know if someone can adjust the car's calculations, probably based on "stock" injector size, to bring the real fuel used in line with display.

I also noted that GPS speed on Waze was lower that speedo display. I use 295 rears vs the stock couple size.
 

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I've corrected the fuel mileage calculations in EFILive but never tried with HP Tuners.
Did a quick look & could not find it... not sure I have all the features in my HP tuners though.
 

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I've corrected the fuel mileage calculations in EFILive but never tried with HP Tuners.
Did a quick look & could not find it... not sure I have all the features in my HP tuners though.
Even that would be a way, I guess, to correct, for what the car's DIC is telling me.

One point of the trip, on interstate all the way, the Caddy was telling me that I was getting 19mpg average and giving me range based on that instead of the 17.4 I actually got.
 

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Do you reset the average after filling up?
 

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Did it on the start of the trip for comparison with new data. That is the final comparisons.
 

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Even accounting for tire size the DIC will be off. I changed my tire size in HPT and it's closer but it regularly tells me that I'm getting 13ish on the DIC but I log every tank and I'm usually at 12 depending on the ethanol content. I'm not sure if there is any compensation in HPT just for the DIC calculation.

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It depends on how your injector data was handled in the tune. If it was handled by doubling the Stoich and halving the flow rate then you also need to half the Instrument Cluster Outputs, and IVT Terms. The Instrument Cluster Outputs controls the DIC calculations. People over look the Instrument Cluster Outputs.

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It depends on how your injector data was handled in the tune. If it was handled by doubling the Stoich and halving the flow rate then you also need to half the Instrument Cluster Outputs, and IVT Terms. The Instrument Cluster Outputs controls the DIC calculations. People over look the Instrument Cluster Outputs.

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I have no idea how it was handled but this would put me on the track to getting the DIC reading closer to real life.

Thanks
 

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Is there a way to adjust the fuel usage display on the DIC that tells you what your instantaneous fuel and average fuel is for estimated range?
Not sure if the V has it, but the E40 ECU on my 06 GTO has a "Fuel Density" value that is only used for the DIC. After my LSA conversion, cam etc, I had to modify that, and now it reads within 1-2% of my actual calculated mileage
 
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