I realize that the computer fuel consumption numbers are not the most accurate, but I am finding my A6 to be about 2MPG after several fill ups., Most of my cars have been within 1MPG, but being 10% off seem like a big margin. Rather disappointing that Audi's trip computer is padding the numbers so much. I'm still happy as I am getting the same MPG as I was in my M37S after 45K miles and that weighed 150 lbs less and did not have AWD. So as the engine breaks in I expect at least another MPG. Just thought it odd that it is that far off.

 

All of my Audis have had their reported MPG be to too optimistic. If the tires have a slightly different circumference, that can make it even more of a difference. If you have the Vag-Com cable, you can make an adjustment to compensate up or down to match your real world gas mileage in the DIS. I just did it to account for a 7% difference from my actual mpg and my DIS is now almost spot on every tank fill.

Correct Fuel consumption in DIS:

{17-Instruments]
[Coding - 07] > [Adaptation - 10]
Channel 3 - change 100 to xxx
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)

 

Mine is typically 1 to 1.5 MPG on the high side.

 

Sorry for the newby question, but I'm new to this and trying to decide if the $350 for the software & cable is worth it. (My 2012's computer seems to be channeling a motivation seminar and is perennially optimistic.)

- Is the above code something that you're entering, or menus that you're navigating to get to the 100 value that you're changing?
- I realize that you posted a list of the items that can be adjusted. When it comes to a specific setting, are you searching forums to determine what other people have found the setting do?...or is there documentation somewhere that lists what's accessible and the range of adjustments possible? (The Ross-Tech website seems to say that although they supply the interface, finding documentation, etc., is up to you.)

Thanks.

 

I guess you missed the "Vag-Com Newbie" thread just below this one but I'll try and answer your questions.

There are many resources for how to use Vag-Com (VCDS) and what is possible. Making most mods is not difficult if you follow the directions that others have already tested. Some of the mods are done in the software with selecting a simple check box, others by changing a value and others by changing the hex code. It's best to not go making changes if you don't know what you're doing and stick to the tried and true mods.

The investment is well worth the $350, i.e. being able to do the many mods available and run diagnostics on your car's systems. Running a full scan when you have an issue or just to check for faults before going in for service is very useful. Also, sometimes a software update done by the dealer can default back and erase your changes - with your own cable, you can reset them easily.

The HEX-USB-CAN interface cable will work on all Audis over at least the last 10 years and those yet to come. All you need is a PC laptop running Windows or a Mac running a PC emulator. The software is free from Ross-Tech. (Stay away from third party cables - most of them will not work or become useless with the next firmware update from Ross-Tech).

Here's the thread with a link that's a bit older but can get you started. Not all the mods shown will work on all Audis, depending on options, model, year, and feature sets - a few have changed or have been added since this list was published. You can search globally in the AW Forums and others for Vag-Com or VCDS for many other tips and mods.

https://www.audiworld.com/forums/sho...&highlight=vag

 

It is definitely optimistic. The biggest gripe I have with it (had the same issue on my Golf TDI) is that is becomes SUPER inaccurate when the tank has about 1/4 or less left in it. For example, in my A6 it will typically say 100 miles left till empty when in reality it will only have about 40-50 miles left until zero. Anyone else have this same issue and is there a solution?

 

You're referring to the distance to empty vs. the overall average mpg readout. The DTE can vary significantly based on your recent driving style as it tries to guess how many miles are left.

 

I am comparing the distance to empty readout versus what I actually get until it truly has zero range. The VW/Audi is BY FAR the worst in this figure. Most of the time when it says I have 100 miles left, I probably only get 40-50 miles TOPS even though my driving style has not changed period. I have found that on other vehicles we have owned, be it BMW, Lexus, etc they are much more accurate.

 

My DTE works as expected. It's a dynamically calculated guess by the computer that gets more accurate as the remaining fuel goes down towards empty. It's a guide, not a precise number, so I use it to judge where to stop for gas but I don't depend on it for accuracy - for that I use my fuel gauge. Perhaps other brands use different DTE algorithms which may explain your experience.

 

Wow--sounds like I'm the Lone Ranger here. After 1 year of ownership and 10,000 miles, I find that the trip computer is consistently 1-2 MPG LOWER than actual consumption. I keep meticulous records and try to be consistent in my fill-ups so I'm confident in my actual numbers. Most every other vehicle I've owned (with a trip computer) has overstated the mileage numbers, but this car is the exception.