Heck, 150KM is nothing to evaluate fuel economy in a brand new car, get some prolong highway trips, have 4 to 5 fuel tanks filled, reset trip on every tank filled, observe it, on recommended mileage change the recommended engine oil, observe it, you can have some thoughts from the dealership regarding your concerns in between first inspection and first engine oil change.
So far, I would suggest you - not to worry about these things rather enjoy and observe the new ride.