:)
When I towed my son's van with the 300Tdi Disco, the Disco got 14 litres/100km (vs 10 litres/100km without a van). However, the 4.6 Rangie on LPG towed the same van far more comfortably, at greater speed (at about 100-110km/h), but consumed 29 litres/100km. That's twice the consumption of the diesel but the LPG was 1/3rd the price. The net difference is that the LPG cot 2/3 the price of diesel.
Refuelling more often is a pain, though. :(

