When it comes to alternative fuels, it seems there are more possibilities out there than ever dreamed of in your philosophy, Horatio. We all know about ethanol (basically fuel made from sugar), hydrogen and electricity, but how about running your car on vegetable oil? Yes, ordinary cooking oil.

It sounds crazy but apparently lots of people in the UK are doing it. It only works with diesel engines but there are plenty available over there and the low cost alone is enough to make it a tempting proposition.

Don’t believe me? Have a look at this Top Gear clip then. Makes you think, doesn’t it?

And when you hear that it works best with used cooking oil, preferably from a Mexican restaurant, well, I guess all those fiery chillies were bound to make a difference…