So I've had my car for about 1.5 months now and put on ~ 1300km on it. I am very satisfied with the car however, I have already used up almost 3 full tanks of fuel. Is this normal gas mileage for a 4matic and will it get better as the engine is broken in?

( I drive in C-mode and my driving habits are pretty calm , if that helps)

Thanks.

Depends what sort of driving you are doing the figures you are showing are about right for urban driving.
Fuel consumption has been discussed in other posts and the concensus is that it takes about 2000 miles / 3000 kms to start seeing an improvement.

this car is bad for fuel economy.
i can only drive about 400km with full tank of gas which is rwd also mind 90% of my driving is within downtown.

since you said you already used 3 tanks of fuel. from my average, that's about 1200km with 3 full tanks.

having said that, i feel really bad now.

btw, people say that driving "S" mode actually consumes less gas.

Yeah not only is it bad on the fuel economy , it's also below average in performance. It looks gorgeous though!

I guess, It's time to start looking into diesel cars eh

It will get better over time, all my past Benz products have picked up mpg when I've past the 25k mile mark or there abouts. Just don't expect to pick up 10mpg..more like 3-5mpg.