My tank was running very empty (light had been on for 20 miles). Range showed 13 left. Put in 5 gallons of 100 octane. Started the car. Showed same level and same range. I couldn't believe my eyes. Put in one more gallon. Same thing. Then I decided to just fill up the rest of the tank with 91. It went up to slightly above 1/2 tank, with range showing only 175 miles while I have just put in about 17 gallons of fuel. Totally puzzled, I drove away. At the light I was staring at my needle on the fuel gauge and wondering what was going on. As I stared at it, I thought I was imagining the needle creeping up. It was! Ever so slowly, the next few minutes saw the needle creeping up very slowly. 7 minutes later, I got to my destination and the needle showed almost full tank. I think if I had left the car running for a few more minutes, it would have shown full tank.
Perhaps there is a faulty sensor for the fuel gauge, but I guess the on-board computer must use data from that gauge to calculate range also.

I guess its time to go visit my dealer.

Anybody else have had a similar problem?

 

yea, had similar problem in an ex-Mercedes CLK 430 before, changed new sensor by dealer and problem solved.

 

i have heard dont keep filling over and over as the sensor or something in there is known to go bad.. and the more times the more wear or something... sorry cant explain exactly.. but my friend @ porsche said.. if you fill it.. just fill it.. dont keep clicking the handle to fill to brim and dont stop half way and then start again. just fill it and wait for the click and be done as lotta people that come into his dealer have problems w/ gauge and something else and this just causes less wear.