Someone can tell me the exact BFSC for a V6 3.9L - year 2002
It is between 0.5 and 0.6.

BSFC = Fuel rate / Power

Fuel rate*is the fuel consumption in grams per second (g·s-1)
Power*is the power produced in Watts where*P*=*Tω

I don't know the fuel consumption

Thanks

 

You can check the Factory service manual, that will be your best bet for info. You can download it from the stickys in this section.