Louise / Lkappenman:
Biodiesel is an alternative fuel for diesel engines. It basically just replaces original diesel BUT your lines etc. have to withstand the more aggressive biodiesel (which is a veggie-oil-ester, really) bubbla is very right !
Bio-Diesel is hence a processed veggie oil product and interesting for diesel owners here in Europe because typically you save on the heavy fuel taxes over here( it saves you same cts to the liter). Its easy to use (bought at the gas station, no modification necessary) but in terms of the environment only second best to pure veggie oil as the refinery process consumes quite some energy.
Veggie Oil is the way to go (over here at least) if you want to save money and help the environment (balanced CO2 emission, no addtl. CO2). Most older engines (and a lot of the new high-tech turbo charged intercooled etc.) diesel can use it as a fuel.
Often you will need 12V
in-line flow-heaters (just like in winter mode for most modern diesels to prevent clogging) to help the fuel and injection pump with the thicker veggie oil at least in cooler climates (or with the long lines in a MH).
To find out about potential lube problems with injection pump (some models need diesel for lube puposes) ask the manufacturer of your vehicle or of the pump (or the www !) or simply TRY:
Start with 25% of veggie oil and work your way up to 100% if things work smoothly. Your old Isuzu should make no problems (not really a sophisticated design), but better be careful while testing.
Here in Europe veggie oil is considered food (true ;-> ) and thus you may save up to 50% compared to normal diesel. You have to buy it at the oil mill or the food discounter, though.
Expect your rig to smell differently, though more like the french fries stand at the country fair
Please keep us posted, if you do test veggie oil.
Great forum, great topic (I am an engineer gotta love those AS) great people.