Adjusting fuel consumption with VAG COM?
 

The instructions on the Audi Enthusiasts web site for adjusting the factor used to calculate our fuel consumption do not seem to be correct for our car (C7 A6) as Channel 3 of Adapation of Instruments is not obvious.

There is another option (irritatingly not numbered) labeled something like 'Display Consumption Correction' that does have a value of 100.

Is this what needs to be changed? Has anyone done this on our C7 A6s?

Thanks in advance.

Here you go:

Correct Fuel consumption in DIS (C7): (Revised)

[17-Instruments]
[Coding - 07] > [Adaptation - 10]
Scroll down about 20 items in the drop down list until you see something like fuel consumption adaptation - change the value from 100 to higher or lower:
Example - if your DIS is consistently off by 7% to your actual calculated mpg:
You RAISE the number to the percentage if DIS is OVER reporting mpg (i.e. 107)
You LOWER the number to the percentage if DIS is UNDER reporting mpg (i.e. 93)

I can confirm this works - I've corrected my mpg.

Wondering what people are finding with the consumption for accuracy? I find mine to be off 7-10% consistently, on the over optimistic side. I am debating purchasing the VAG COM as there a few tweaks I would like to make, just trying to justify the price to make a handful of cosmetic tweaks.

All of my Audis' DIS mpg readouts have been optimistic. My A6 was about 6% too high and now is regularly less than 1% after I made the correction.

Keep in mind that the VCDS is more useful than for just mods. For example, It can tell you if anything is wrong and where a problem lies. I run a scan to see if anything has been acting up before I take my car in for scheduled service.

Is the VAG-COM worth getting if Apple products are used? I assume you need some computer to go with?
How about ipad and iphone apps that work with the OBD2 plug, are they of functional value or more for giggles?
What will it save/give me in performance and fixing problems?
Thank you.

The VCDS software for use with their cable is PC only but can be used with any of the available PC Windows emulators for the Mac.

My understanding is, outside of scans, other OBD devices will not have the scope or ability to do many or most of the mods provided by VCDS. Also, they may not have the benefit of the VCDS easy coding options. Others having experience with these devices and software can chime in here.

The VCDS has the ability to dive deep into the coding of an Audi or VW and can be a powerful diagnostic tool. However, beyond the long list of common mods and scans that the casual user can easily employ, it requires some expertise to avoid causing malfunction or even damage to the car's electronics and operation.

I've had my VCDS cable for several years and have used it on all four of my past and present Audis. Although I stick only to the proven mods and scans, I've found it to be very useful and well worth the $349 investment.

Just curious, in getting back to the fuel economy question: how are you guys calculating your fuel economy? I only ask because Motor Trend had a big write up this past issue about employing some UK company to calculate their economy based on capturing tailpipe emissions.

I always thought the "fill it until auto-shutoff, zero out trip odometer, refill later until auto shutoff" was pretty accurate, but they say even on the same pump you can see up to 4/10 gallon differences.

The trouble is when I try this the software (for this module) does NOT list channels by number nor can you choose one by number. It list them by a text description and the 3rd option down does not seem right. It has a binary setting (active/inactive). However like 20 down the list is a descriptor labeled something like 'correct DIS consumption' that does have a value of 100. Is this what I change.

I have done all the other VAG COM mods and this is the only one that does not match the instructions.

You're right - I now remember it didn't exactly match up. It's the one with the "100". Follow the instructions for changing the value.

out of curiosity: what's COM in VAG-COM? command? I know VAG is volkswagen audi group.