My dad has his landrover on LPG and it is bloody great.
LPG (or what is used to make it) comes directly from the oil well and used to be burnt to provide heating and power on some of the rigs. I think a great deal has come from the north sea oil wells as these produce a lower grade oil that can't be Kracked into the same quallity petrolium as the middle east can supply, though this lower grade has a lot more gas run off.
The benerfit I know of-
-Much, much better for the enviroment
-Higher octane so engine runs nicely
-Doesn't coke the engine
-Cheaper fuel (about 1/2 the price)
-Very simple injection systems
The down sides are:
-can't go on the channel tunnel
-high cost for conversion (good system from around ?1500 fitted)
-trouble with insurance, some companies won't touch you
-If you have an old points distributor system it's not quite as good as with an EFI system.
While it is theoretically is more explosive as it a compressed gas product the tanks are manufactured to a far higher quallity so I recon you probably run about the same risk. LPG systems have a lot more safety device fitted and the tanks can only be filled to about 60/70% capacity.
As for drivablillity you don't notice any difference apart from the engine being a little quieter.
it doesn't contain any oil, so your cylinders aren't greased while driving --> never abuse your engine, or drive more than 100km, while on LPG
-I have never heard of this before, but on an internal combustion engine the engine is usually lubricated by the oil in the sump. I have heard of lpg causing problems with carbs (especially SU type) where the pistons would rust up due to not being covered in fuel.
All I know is my dad truck has done 70K miles on LPG with no problem what so ever.
It think it's great, the only other thing to think about is A) the kit is pretty heavy so make sure you haven't got a gutless piece of crap fiesta to haul it around.
B) it's pretty bulky, so unless your going to remove your old tank you might have to lose your spare tire to fit it.
Sorry for the essay got a little carried away