hapydazy said:
and again, I've learned something new! I had no idea that you could run a diesel on vegetable oil
When Rudolf Diesel invented his engine, it was designed to burn pretty much any carbon rich fluids like diesel, vegetable oil and peanut oil.
Vegetable oil is surprisingly very similar to diesel chemically - the main difference is that vegetable oil is thicker, and is slightly better at 'cleaning' and lubricating.
The problem with some modern cars is that the fuel injector is quite delicate and can get corroded by vegetable oil, so it's important to research whether it's safe to run vegetable oil as a fuel in your particular diesel car. I've had no problems with my 1992 Land Rover!
Basically - if your injector and engine can deal with vegetable oil (
handy database here), you have two options.
A. Add a percentage of vegetable oil to your regular diesel - to dilute the thicker oil so you don't need to modify the car at all. In winter (when the cold makes oil thicker) I run 10-15% vegetable oil, and in the summer I plan to increase this to 30-40% when it's warmer. (Some run 50%+)
B. You can have a modification kit fitted which pre-heats the vegetable oil before it gets to your engine - this can cost £400-500 but will allow you to run 100% vegetable oil!
At the moment, you can find vegetable oil at the supermarket for 75-80p a litre - more expensive than 6 months ago (65p), but I suspect the price is increasing because more people are doing this. I noticed that last year, all the supermarkets stopped selling 'smart price' or 'value' vegetable oil
Even better - find a chip shop or restaurant and offer to take away their waste vegetable oil for free! You can then filter this with a fine cloth or other fine filtering material to get the food bits out and put it in your car the same as new veg oil - this won't cost you anything! Some people fill water butts with waste oil for this purpose.
The UK government used to tax any alternative fuels, which made it not much cheaper than diesel - but they now allow a personal allowance of
2500 litres a year before you have to declare it at all and pay tax.
If you own a diesel, do a lot of miles and are not too precious about your car (there's no evidence that running vegetable oil harms your engine, but to be honest there's not been huge amounts of research done), then I'd recommend looking into this option!
My car runs slightly quieter with vegetable oil, and it also cleans out the engine better than diesel to maintain performance. It's essentially 'carbon neutral' (The vegetable oil producing crop absorbs the same amount of CO2 that burning in my engine releases), and I have the added advantage of my exhaust fumes smelling a little bit like a chip shop!
I think it's only gonna get worse 
also i think Australia is the 4th country with cheapest petrol prices??
We've just always called it gas over here or gasoline... I've never known that the gas part was just vapors, so thanks for educating the American on that one 
