Articles by Clark Williams-Derry

Big greenish taxi

As gas prices have risen, hybrids have become a substantially better buy than they once were. Still, it depends on how much you drive: the more miles you log, the more money a hybrid can save you.

So I'm heartened (though far from shocked) to see that cab companies are starting to realize this. Cabbies drive a lot. That's their job, after all. And higher gas prices mean that they're starting to run up enormous fuel bills, which means that switching to hybrids offers an immediate benefit to a cabbie's bottom line.

Speedboat powered with ass fat.

Uh, folks, is this story real?

Saving the planet can be a real pain in the butt. Just ask Peter Bethune, who's powering his speedboat with biodiesel made of fat from his backside.

That's right, Wired is reporting that some dude turned his own liposuction fat into a liter of biodiesel. OK, so he admits it's just a symbolic gesture -- part of a publicity stunt to promote renewable fuels. The main event is breaking the round-the-world speed boat record in a rad-looking, biodiesel-powered boat.

Assuming this isn't a hoax, is it even a good idea? I mean, leaving aside the fact that speed boats are energy hogs (and an outsized environmental offender, according to this book), does it help promote renewable fuels to link the concepts of "biodiesel" and "ass lard" in people's minds?

On speed

Just a public service announcement: speeding wastes gas. In fact, as the graph to the right shows, the typical car engine is most efficient at speeds of about 50 miles per hour (about 80 kph). Well, really there's a broad plateau from about 30 mph/50 kph to about 55 mph/90 kph. Outside that plateau, though, fuel efficiency drops off substantially.

The problem is that highway traffic tends to move substantially faster than the point of maximum efficiency. Even if you wanted to save gas by, say, driving at 50 mph on the freeway, you might not feel safe among all the speedsters and tailgaters. And your feelings would probably be accurate; although the relationship between speed and safety can be pretty complicated, the evidence suggests that driving significantly slower (or faster) than the average traffic speed is a good way to get in a collision. Which in turn suggests that the way our highways are engineered may force drivers to make a choice between saving a bit of fuel and saving their lives.

Feebird!

Continuing with the recent spate of attention to "feebates," Republican senator Gordon Smith from Oregon floated the feebate concept at a recent congressional hearing. Bully for him!

With gas prices as high as they are, and the security costs of ensuring North America's petroleum supplies (think, say, of the cost of America's military involvement in Iraq), feebates are an idea whose time has come. And Smith's support suggests that the idea may even have some bipartisan appeal.

The basic idea of feebates is to charge car buyers an extra fee when they buy a gas guzzler, and rebate that money to people who buy efficient vehicles. The amount of the fee or rebate depends on the miles-per-gallon rating of the vehicle, compared with the average for all new cars sold. (For more details, see here).

The beauty of feebates is that they create incentives for continuous improvements to vehicle efficiency. That is, no matter how efficient the average car or truck becomes, feebates will still help boost sales of the most efficient vehicles on the market.