LPG vs ULP - Ford Falcon

Intro

Here's some fuel economy stats from my LPG Falcon BF sedan, compared to the ULP model I drove while my
LPG was being serviced.

LPG

Best 10.5 L / 100km @ $0.60/L = $6.30 / 100km
Avg 11.5
Worst 12.5

ULP

Best 7.5 L / 100km @ $1.50/L = $11.25 / 100km

Summary

You use more 25% more LPG fuel per distance (as LPG has lower energy density), but it costs 40% of ULP, making it overall half the price to run.

You lose some power on the LPG model (10-20%) but the 4.0L V6 has plenty. Servicing is slightly more expensive, but not enough to cancel out the cost benefit. Plus it has less dirty emissions as it burns very cleanly compared to ULP.