Do You Ignore The Fuel Gauge?

[CO2SLAVE]

I had assumed that knowing that a car's fuel gauge was inaccurate was obvious?

Obvious to many on this forum maybe because they don't expect any better, but my BMW 1 series analogue fuel gauge was absolutely linear in its readings , and as mentioned before - you would have to be "very brave or very stupid " to run the range to zero , because I did it once ( I think I was brave but I am sure that many will correct me on this) and I put 49 ltrs into a 50ltr tank so it was a little too close to empty for comfort.

As an example of the benefits to my original post - on wednesday night I had done 408 miles on a tank and I needed to be out that evening ( in my wifes car) so I had no time or inclination to go 3 or 4 miles out of my way to fill up ,but I had to do approx 100 miles the next day so I did a quick calculation ;

The mpg reading for the tank said 59 or so mpg so i reckoned I could do 590 miles on a 10 gallon tank less 60miles ( 40miles for mpg error + 20 miles sphincter factor) so I reckoned I could safely do 530miles.

So I very bravely and/or stupidly did my daily commute.

The result ? - filled up last night and put in 41.5ltrs did a total of 504miles , so I basically had a comfortable reserve of 3.5ltrs (43 miles of fuel at 55mpg)

And I did it on my way so no wasted 3 or 4 miles of fuel !!

The range went to zero about 408 miles and I am not sure at what point the blocky thingy was flashing but it was at least 60-70 miles.

**********************This is why I ignore the fuel gauge**********************

[timberwolf]

I had assumed that knowing that a car's fuel gauge was inaccurate was obvious?

Obvious to many on this forum maybe because they don't expect any better, but my BMW 1 series analogue fuel gauge was absolutely linear in its readings , and as mentioned before - you would have to be "very brave or very stupid " to run the range to zero , because I did it once ( I think I was brave but I am sure that many will correct me on this) and I put 49 ltrs into a 50ltr tank so it was a little too close to empty for comfort.

Ah, I meant generally across makes and models, but maybe I've just had lots of crappy cars when it comes to the accuracy of the fuel gauge.

And thanks to the others for posting about the complexity of weight vs mpg. I'd had hoped that there would be a simplified formula (giving a close enough figure) or graph for this sort of thing.

[jamesw]

I agree with the OP and find this topic interesting as my Auris is never empty of fuel when the gauge tells me its got 0 miles left in the tank! But I am also not getting the MPG others are getting but that is most likely to be due to the angle of my right foot however hard I try!

[cuius]

I've run my Auris down to "empty" twice, and now know that I've 140km left