Super high fuel consumption

[aabdelhamid]

I drive my car mostly on high non-congested highways. I recently started monitoring the fuel consumption and was shocked when I learnt my car is averaging 16.3 l/100 km. Seems super high to me specially that the E39 only consumes average 9 lit/100km with the same mode of driving. please tell if this is OK and if not, then what shall I do to prevent this.

[shogun]

9.2/13.6
Consumption in Liter/100km at constant 120km/h / city traffic according to the manual in Germany.

Now is winter time and the car uses more fuel due to the longer cold start time, that might be one reason.

[aabdelhamid]

d

[shogun]

As I mentioned:
9.2 is for constant 120 kmh
13.6 ltr is for city traffic.
It is for a 520i M20B20 engine
http://www.e34.de/e34/unterhalt.htm

Verbrauch means fuel consumption in liters per 100 km. First number is for constant 120 kmh, second number is for city traffic.
That is in the EU a fixed rule for the car makers to show these data in the brochures/manuals.
Usually actual consumption is higher, as these tests are made under optimum conditions.

[BillionPa]

start with O2 sensor if its old. that usually does the trick.

[Alexlind123]

start with O2 sensor if its old. that usually does the trick.

Order one from racingking, if you search you can find the link for his special sale. Its a really good price, i ordered one a few days ago.

[E34-520iSE]

I drive my car mostly on high non-congested highways. I recently started monitoring the fuel consumption and was shocked when I learnt my car is averaging 16.3 l/100 km. Seems super high to me specially that the E39 only consumes average 9 lit/100km with the same mode of driving. please tell if this is OK and if not, then what shall I do to prevent this.
I have one and it's not too good on petrol. A 2ltr M50 or any 2.5 ltr would show significantly better fuel economy. I have recently adjusted my fuel mixture which has made quite an impact in long distance fuel consumption. Also the engine doesn't run 'sooty' anymore. I can't comment on the O2 sensor as UK cars like mine don't have them.

HTH,

Shaun M

[Zeuk in Oz]

My M20 2.5 uses 8-9 litres per 100 km in mixed driving.

There must be something very wrong.

Checking or just replacing your oxygen sensor might be a useful first step.