Whats your average speed say on the computer??

just gotta service which totalled ~$1400
Belts, throttle clean, tyres (didnt actually ask but they were bold) etc..

And my fuel is still on 13.8L/100km with an average speed of 31kmph !
I gotta VRX 3.5 5 speed tiptronic left in auto all the time. Does anyone know if its my gearbox or something thats using a lot??