You need an OBD II interface that translates the ISO 9141 protocol into serial data that can then be displayed by a program running on your CAR PC.
The data you want is available on the OBD II connector, not the I - Bus in your vehicle.
We sell an interface that will do that see www.obdpros.com.
In order to show fuel consumption you would need to purchase a program such as scanmaster that does the fuel calculations, for all the other data the free programs that ship with the OBDpro will be sufficient.
I would recommend you try the free programs with the interface and then decide if you want to spend the money on scanmaster (an excellent program BTW)