As those of you who do me the honour of reading this column on a regular basis will know, I have pretty straightforward views on the business of saving fuel. Saving fuel is for fools.

I don't even accept that, for some people, driving is a necessary evil, and that it should be done as cheaply as possible. Driving is not necessary at all, because trains and buses are very good these days and still cheaper in real terms. So kindly use them, and free up more road space for people like me who actually enjoy cars.

And as cars are my hobby, I can't really object to having to spend money on petrol, rather in the way that fishermen can't really object to having to buy maggots, and fans of hotel TV can't reasonably object to the price of Kleenex. Given the choice between a car that I'd enjoy driving and one that would save me a tenner every so often, I would always spend the extra £10.

I even have an environmental argument in favour of thirsty cars. Everyone tells me that burning fossil fuels is a bad thing, and that it is destroying lives.

In which case, surely it makes sense to buy something like an old Bentley or a Sixties' American muscle car and do your bit to help rid the world of this stuff. That way it won't be around to blight the lives of your grandchildren.

However, I've now changed my mind. I've changed it so much that I've sold my ageing Range Rover and bought a new 1.2-litre Fiat Panda, a car that steadfastly refuses to drop below 40mpg even if I thrash it and which, if I'm not paying attention, will readily crack 50. It saves petrol, and that is something we need to do.

We need to save petrol because the nation is in great peril. The nation is in great peril because of enthusiasm for alternative fuels. And amongst alternative fuels the most fashionable is biodiesel.

I don't like biodiesel; 'tis a silly fuel. For a start, it smells all wrong. A while back we were filming Top Gear near a farm where the stuff is made, and at one point the farmer went off to the bank in his biofuel-powered old Volvo.

The sensation was similar to that experienced on driving past a kebab shop, only now the kebab shop seemed to be driving past me. That's confusing to an olfactory system conditioned over many decades. It's like Pavlov ringing his little bell then kicking his dog smartly up the arse.

Unfortunately, biodiesel also smells pretty bad long before it makes it to the exhaust pipe. If I've understood The Archers correctly, it is made from oilseed rape, which stinks to high heaven just growing in a field.

It's also an ugly yellow colour and is completely ruining the countryside, which, after all, is for driving through and admiring. England is supposed to be a green and pleasant land. I haven't given permission for it to be turned into a lurid-yellow hell that whiffs of unpleasant hair products.