With full tank I start driving and about 80 miles (first quarter of the tank) everyting is fine. Then the fuel gauge starts playing tricks on me. Sometimes as I drive I notice that it indicates I have more gas than what I had when I started my commute (approx 20 miles). Then, if I multiply 80 by 4, I would assume that I should travel 320 miles with a full gas tank. Wrong! It only goes for max 280 miles. That's because sometimes it shows me that I used up a quarter of the tank in only 20 miles....<br>Well, it's annoying as Hell and the dealer swears it works as designed by manufacturer. Did anybody experience it?<br>I got a '98 A4 2.8Q.

The computer re-averages the reading from your fuel tank level meter with the previous 25 readings. There is only one reader device in the fuel tank, so it has to average the readings. Otherwise, your readings would be horribly far off when you hit a bump, parked uphill, or were driving downhill. Agreed, the system doesn't work perfectly, and you need to second-guess the computer sometimes, but there are worse things in life.<p>Cameron<br>

I can do about 200 miles and it is just a hair below 1/2. From 1/2 to empty less than 310 miles on odometer.

I have watched this take place for 2 years now but have observed that the fluctuation (+/- 1/8 tank)does not take place in the summer when I have my air conditioner on all the time and fluctuates in the winter when I have my heater on (set to 75). Also the fluctuation does not occur on start up on a cold day but comes in after the interior starts heating up. <p>For some reason heat affects the averaging module or the guage. <p>The bottom line is set you trip odometer at every fill up and get gas at 300 miles.....you will survive!

nt<br>

I'm sure that the guage is designed to operate the way it does, but that's no excuse. It's badly designed!<p>No flames, now, but I have a 99 BMW 323i (my wife has an A4) and the fuel guage NEVER oscillates, and progresses evenly from full to empty. The warning light is supposed to come on at 2.1 gallons left, and once it's on, it stays on. As a test, I filled up just as the warning light came on. It took exactly 14.5 gallons to fill up the 16.6 gallon capacity tank.<p>Now, if BMW can do it, shouldn't Audi be able to?