Fuel gauge, not mileage, may be bad!
 

95 850 Turbo wagon - 82k miles

As some of you may recall from my "welcome" post, I calculated that I was getting about 13-14 mpg based on the gauge and "miles to empty" read out.

So, when the tank was low (around the "6" gallon mark) i'd fill it up and it would only take 7-8 gallons before the filler clicked. My first thought was that maybe the numbers on the gauge (up to 18) were some kind of european conversion and that the cars came with very small tanks. :)

What I've come to realize is that the gauge is erratic and mostly wrong, and so might be the computer calculations to "miles per gallon" (average 12.9 currently) and "miles to empty" and is based on a faulty sensor.

Anyone hear of this? Is the fix simply to replace the (in tank...ugg?) sensor? Robert? :) I did a "search" and couldn't find any mention of it.

After the fill up, where is the gauge? Have you tried to calculate mileage manually? The issue can be the cluster.

If you are getting 14 mpg you really need to find out why. Any codes?

I feel sure the fuel mileage calculator wouldn't use the fuel gauge. There are several good reasons why a computer programmer wouldn't do that, and I'll just sum them up by saying it's inaccurate.

When I calculate fuel mileage every 2 weeks, using a cocktail napkin, I don't even use the fuel gauge. You know why? It's inaccurate.