well i have used and got 5 highway bowsers for both jet and avgas. I have a 1000 litre one that has a polyprop liner all I did was put a filter on it (aviation one) have put 25000 litres for it and the heli is still going ! Asked th manufacturer what the difference was apart from £2500 extra in price, answer bonding cable and a filter (bonding reel about £200 and a filter bowl and filter about £300) seems to me profiteering !