Just finished a trip from Mt Barker Sth Aus through Ouyen - Swan Hill - Bendigo - Ballarat and return the same way including running around the touristy thing. TE Sedan with 3.0ltr and auto.
Running Dual fuel, I emptied the LPG 66.7 ltr refilled for 642km's and 52ltr petrol for 560km's. Highway speed was 98 km/h on cruise.
Around home the LPG gives me 480km and the petrol 600km of freeway hills and city driving.

Can't remember how to break it down to ltr per 100 but whatever it is, I am pretty happy with these figures.