Lies, Misinformation and Jeremy Clarkson

• policy
• fuel
• globalwarming
• idiotswithopinions

A lot of people (mainly car drivers and lovers) have gleefully told me about the 'test' conducted on Top Gear which 'showed the Prius (a hybrid eco-car) wasn't that fuel efficient'. In case you haven't seen it, the clip can be watched here, unless it's been taken down by the BBC (the kitten accepts no responsibility for objects thrown at screen in an attempt to silence Jeremy Clarkson).

For those with no desire to watch it, the 'test' was this: the Prius is driven at top speed for 10 laps. A BMW follows at the same speed. Fuel consumption is compared. The Prius did 17.2 miles per gallon, the BMW 19.4. Conclusion: the BMW is more fuel efficient than the Prius, drive your BMWs with pride, o ye petrolheads!

Surprisingly from Mr. Clarkson, this argument is illogical. It's not possible to go from one specific circumstance (the fact it uses more fuel being driven flat out round a racetrack than a BMW) to the general case (the Prius is less efficient than the BMW). While this result may be valid for high-speed driving, the Prius is not designed to be efficient when driven this way. Which seems quite reasonable, given most people who aren't Jeremy Clarkson don't drive at full speed all the time.

The Prius has two engines, which can both provide propulsion, as Jeremy clearly knows from when he tested it earlier. The electric propulsion system consists of an electric motor and a big nickel-metal hydride battery, just like the AA rechargeable batteries that you (hopefully) use in your cameras. The battery charges using energy generated by the petrol engine, which is lost in a traditional car. It also scavenges from the energy applied to brake the car, which again is normally wasted. Once charged, the car can run at low speeds just using the electric battery and motor — zero emissions, and zero petrol use. The 2008 model can only do this for a few miles before the batteries run out, but the next model due out uses lithium-ion batteries instead (as used in mobile phones) and can run for up to 30 miles without conking out. The later model is also equipped for mains charging. At current leccy prices, 30 miles worth of charge would cost you 22p.1

At higher speeds, the car just uses a standard petrol engine, nothing special. At even higher speeds, both methods are used at once to get more performance. So in the circumstances it was pitted against the BMW, the petrol engine would have been running at top speed, with some assistance from the electric motor. And yes, it is less efficient at that speed than a BMW. However, the modifications which make the Prius more environmentally friendly (energy scavenging and the option of running on electricity only) only kick in at slow speeds or when stopping and starting, as in city driving. So, Top Gear has succeeded in proving that if you don't use the Prius' energy-saving features, it doesn't save energy. Big woop.

It's also been said that, if you consider the costs involved in making the car in the first place, all modern cars look pretty shabby; the squirrel crushing, deer-smacking Land Rover comes out best when you consider the energy consumption, carbon emissions and raw materials used in making the car in the first place. This is because Land Rovers don't break down: they continue working for as long as you want them to keep working or you can be bothered to drive a car with no mod cons. You'll probably break before it does. But when you're considering the car's performance over a lifetime, there's one crucial fact: how long is that lifetime? The first Land Rover was launched in 1948, so it's had over half a century to keep going and not take up more resources. Of course that's going to do better than more modern cars which have only been made for a few years, so even if they are going to be as long-lasting as the Land Rover, the numbers won't show it yet.

Finally, hybrid-haters mention that lithium-ion batteries and the other rare metals they use to make the Prius are a bitch to get rid of. Not arguing; however, most modern products contain nasty chemicals that poison the water or the air. This doesn't seem to bother them when it comes to their plasma screens, circuit boards or mobile phones, though. Just because the Prius is no better than competitors here doesn't detract from its other achievements. I suppose you could say that it's somewhat hypocritical to produce an eco car without wholly eco-friendly parts, but it's more hypocritical to claim to care about the environment and then not do anything about it because none of the efforts to help are perfect.

Bottom line: cars are destructive. A lot of people don't need a car, or don't need to make the amount of journeys they do with theirs. If you have to have a car, a Prius is a good choice. Yes, it's expensive: but the price of petrol isn't going to drop, and the lower running costs should hopefully make the £17,000 price tag more palatable. In the meantime, why not take public transport if you live in a decent sized city? If you don't, harass your MP into fighting for better transport. Cars should be a privilege, not a right; definitely not a necessity.

1. Although do remember that electricity isn't automatically 'clean energy'. There's no point running you car on electricity to save fossil fuels, if that electricity is produced by burning fossil fuels. Luckily, you can get green electricity which doesn't involve burning dead things. ←