fuel efficiency 300 e diesel

[eek]

I have a 1999 300 e diesel. When the tank is filled, I only get about 60 miles from the time the gauge goes from full tank to 3/4 full. I assume this should be five gallons of fuel, but that would mean I'm only getting 12 miles per gallon. After the gauge hits 3/4 tank I get about 140 miles per quarter tank in city driving which seems about right. Is this normal ( is ther a fault in the gauge?) or do I perhaps have a leak in upper part of fuel tank ?

 

[jberks]

Guages often fall almost instantly from full to 3/4. Basically the scale isn't that accurate. In fact BMW got around it in the old days by having a wide gap between full and 3/4 and a very small one between 1/4 and 0. I wouldn't read anything into this but rather do an overall mpg check from full to full. Any problem will show up here though I doubt you have a leak as one this severe would leave a massive greasy residue all over the back of your car and I doubt you'd have any traction left on the rear tyres.
I suspect what you see is perfectly normal.

 

[Ger D]

Fill the Tank.
Note the mileage.
Drive the car until its about 1/4 full.
Re-fill the tank noting the volume of Fuel required and the new mileage.
This will allow you to calculate the MPG you are getting.
For Mixed Driving you will end up with a figure of 28 to 31 MPG.
For open road driving you'll get 32 to 35 MPG.
If you get any more than this let me know your secret!
Happy Driving!