i would have thought

natural gas= any naturally formed gas eg methane, etc etc.

petroleum gas=LPG Liquified Petroleum Gas

i tend to think along troys lines a bit.

keep the discussion coming guys
cheers Nick.

__________________
Cheers
Nick.

Roidio 2001 Holden Rodeo 4x4 2.8L TD. 2.5" Straight through exhaust sytem, heat exchanger shower system. 2" Body Lift,
And lots of fruit, B100 for 25,000 no problems.

Elsa 1983 Mercedes-Benz W123 300D. The Fastest Merc in Oz, Loving B100 Burgers