190E Fuel economy????

[190ESport]

Hello all pros

Here is one of the most recent difficulties i have been experiencing with my beloved 190E. Lately the fuel economy
of the car is very poor and i cannot determine why exactly it is like that. So i was just checking to compare with all of you who have 190E 2.3 8valve to see if your consumption is the same.
In the pic below you can see how the Economy needle is not at the minimum when the car is cold and in gear (D) with the brake pedal applied (car not moving). When i got this car i think the needle never use to move when the car was idling or when it was in gear like that. Only on a hard depress of the pedal on acceleration or on the highway which is normal im presuming.
I was followed by my friend and we were racing on the highway and he said that the car was smoking a bit grey when it was fully floored (speeds 150km/h and above in summer time).

I had somebody press the gas pedal while the car wasnt in motion and at 4000 rpm there is no smoke but the smell of unburned gasoline if present in the exaust fumes. The car takes in about 12/14 L per 100 km which is terrible. Im wondering is there any way i can adjust the fuel or maybe replace the O2 Sensor or somethin that will improve the fuel economy. I have not noticed loss of power of anything like that.

Recent things i did on the car include:
Oil change with air filter change
Fuel filter changed
Resonator changed - no rear muffler section (straight pipe)

the car speks are
190 E 2.3 8 valve 1987
120 000km on the clock
all original (engine never touched)

All feedback is highly appreciated... thanks guys!!