Quite a big range between conversions and driving style.
5 to 7 km/l is what I would bear in mind for an older 1UZ in Gen 2. VVti with auto 6-8 km/l
On my 1UZ manual with full Toyota diffs, punga driving in the city, I would still get 4. Rally with exhausts was 3-4 while with open headers 2-3.