I have just bought a 190 Mercedes 2.0E 1989 last week.
The car has very good shape, full original painting, no rust at all.
Everything is working, the engine runs smooth, pulls OK, no smoke, great idle, but a little bit high I think (about 950).

My problem is that I got pretty low mpg, and I know it should be way better.
Just consumed my first tank of gas, it made only 306 km by using 50 liters of gas, which makes about 14 MPG or 16.5 l/100km.
AFAIK it should consume somewhat between 20-30 mpg depending on driving style/road conditions, etc.

I don't know if it's related to consumption in any way, but the engine starts perfectly when the engine is cold,
but drops RPM for couple of seconds when started warm. (Without pushing the acceleration pedal.)
After a few seconds, it flattens nicely (at about 950 rpm).

I have replaced the air filter and the plugs today, so I may tell after a few days if that changed anything.
There's no smell of unburnt petrol from the exhaust, and the all of the old plugs looked quite nice red/brown, no black deposits, oil, etc.
Do you guys any idea where I should start fixing this?

Any help is highly appreciated!

Thanks in advance,
moire76