Hi Jjroy,
to define the calculation method for fleet consumption first have to define measurement unit in CUNI in unit dimension SURINV.
for KM per fuel define KM/L, KM/KG(CNG)
And in setting for fleet management >>define measurement unit.>>
select the SI unit M2I(unit group- M-2)>> within define your measurement unit KM/L or KM/KG.
in Calculation configuration>> define ur calculation method X, measurement unit, primary counter, fuel counter..
Regards,
Rakesh