There are many facets to green motoring, but for some the prospect of buying a new hybrid or electric car is neither realistic nor desirable.
For these people, biofuels may be an option, particularly those recycled from other products.
Biodiesel made from used cooking oils is one such fuel, and is becoming a popular option for those with access to large quantities of cooking oil. On a large scale, it even powers large portions of McDonalds' delivery trucks.
With the right tools though, you can make it in your garage. Biobot, a UK company, sells just such a tool for converting waste oil into usable biodiesel.
The Biobot 20 retails for around $655, says Gizmag, but a typical 15-liter yield of biodiesel could cost as little as $1 per gallon in necessary methanol and sodium hydroxide--while the raw cooking oil itself is, in theory, completely free.
Making the biodiesel is quite simple, if time-consuming.
Used oil is poured into the reaction chamber, which is then heated while you agitate the mixture manually with the handle. A little sodium hydroxide is added to four liters of methanol, and this solution is fed into the oil.
Over 12-24 hours this separates glycerin from the biodiesel, which is then pumped through with water to clean it. Another heating period removes residual traces of water.
If you have the time to set aside to a little mixing and adding ingredients, it could prove a very cheap way of running a diesel vehicle--and as a recycled fuel, a fairly green way at that.
But if you do a lot of miles, or spend a lot of time away from home, you might not be able to make it quick enough to have a continual supply.
You might also see some side-effects from all that deep-fried food...