Gassing up for less

tauringhuang.

Sep 12th 2008
From Economist.com

Natural gas could be a better choice than petrol


THE inmates at Mayhem Manor need a new set of wheels. The three-ton kidmobile acquired when petrol cost around $2 per gallon has mercifully gone back to its maker.

After careful running-in, a change in driving habits and a software upgrade for the engine-management system, your correspondent eventually boosted the Land Rover’s fuel consumption from 11mpg to a giddy 13mpg. With premium petrol continuing to hover around $4 a gallon, something like double that is needed if running costs are to be returned to their level of a few years ago.

What about a Prius? Toyota’s cute little petrol-electric hybrid seats five, costs a modest $22,000 for starters, and gets 46mpg. It is no longer just for tree-huggers, fashionistas and Hollywood celebrities. Unable to meet demand, Toyota is rushing to convert one of its idle truck plants in Mississippi to double its Prius output.

AP

Clean machine, no gasolineBut while your correspondent admires the Prius’s hybrid-drive system, he thinks the rest of the vehicle leaves a lot to be desired. Driven quickly on winding roads—or if simply trying to avoid an imminent accident—all that extra battery and engine weight plus skinny wheels and staid suspension settings don’t exactly endow the Prius with sure-footed stability.

Then there’s the premium dealers are tacking on the Prius and other hybrids because of the current short supply. Last week, one of the largest Ford dealers in Los Angeles wanted an extra “market adjustment” fee of $6,000 for a mouldy old Ford Escape hybrid, which a year ago was going for several grand less than its $29,300 sticker price.

Readers may recall your correspondent’s enthusiasm for diesel engines (see here, here and here). With low-sulphur diesel now available in America, and a new crop of lean, clean diesel cars coming ashore from Europe, a modern common-rail, turbocharged diesel car capable of 50mpg or more ought to be the answer.

And so it would be were it not for the global shortage of diesel fuel. The thirst for such fuel in Europe (where 60% of all new cars are diesels) and now in China and India, too, has driven up pump prices everywhere—in America, it costs between 10% and 20% more than petrol. Such a margin pretty well cancels out the diesel’s superior efficiency.

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All of which has made your correspondent recall his early days as a motoring journalist. In the aftermath of the first oil shock, when everyone was desperate for alternative fuels, he tested a family car in Britain which, at the flip of a switch, could run on either natural gas or petrol. The transition from one to the other was barely noticeable. And the car seemed to run just as well on either.

The installation was reasonably cheap, and could be retro-fitted to practically any car. The problem was the fuel supply. Thanks to the huge methane field beneath the North Sea, Britain was awash in natural gas. Unfortunately, the stuff that powered the duel-fuel car was liquefied natural gas (LNG) rather than the gaseous form piped around the country for heating and cooking purposes.

Why liquefy a gas instead of leaving it as a vapour? Because it dramatically reduces the volume needed for storing it—some 600-fold in the case of natural gas.

But liquefaction doesn’t come cheap. To turn natural gas into a liquid, the temperature has to be lowered to -160 degrees centigrade. And to keep it from evaporating, LNG has to be kept refrigerated in an expensive cryogenic tank. In Britain during the 1970s, there were only a handful of places where you could buy LNG by the gallon.

The Japanese, sensibly, never tried to put LNG in their cars. They opted instead for compressed natural gas (CNG), even though it meant installing a bulky pressure vessel in the boot. To this day, most Japanese taxis run on CNG—and, as a consequence, have little space for luggage. That, and the limited range between fill-ups, are the only real negatives.

On the plus side, a CNG car gets about the same fuel economy as its petrol equivalent, but emits 80% less smog-forming nitrogen oxides. The Environment Protection Agency rates the Honda Civic GX—the only production car sold in America that runs on CNG—even cleaner than the Toyota Prius.

As the greenest car in the country, the Civic GX qualifies for a $4,000 tax credit. In California, it gets to ride in the carpool lane on freeways, even when the driver is the only person aboard. And it qualifies for free parking in environmentally minded cities like Los Angeles, Santa Monica and San Diego.

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Best of all, the price at the pump for CNG is 40% less than petrol. That means $2.30 a gallon of gasoline equivalent compared with $3.90 a gallon for regular petrol.

Ah, but where can you gas up? Your correspondent has one CNG station in his neighbourhood. But there are only 150 or so public CNG stations between Los Angeles and the Mexican border, and no more than 250 in all of California.

With a 200-mile range, the Civic GX is hardly the vehicle to take on a cross-country road trip. As a commuter car, however, the little CNG-powered Honda is hard to beat—all the more so if you can gas it up at home at night.

The ability to do just that is what’s making CNG look so attractive. A Canadian firm called FuelMaker now supplies a CNG home-refuelling unit that can replenish the fuel for a 50-mile daily commute in four hours.

Installed in the garage and connected to the domestic gas and electricity supplies, the simple compressor unit, called Phill, pumps out CNG for around $1.60 a gallon of gasoline equivalent. Phill costs around $3,400 to buy, but leasing deals are common. Either way, installing a CNG station gives the home-owner a $1,000 tax credit.

What’s not to like about such a deal? Only one thing: your correspondent isn’t wild about the Honda Civic—whether fuelled by petrol or natural gas.

Where Americans have only one CNG car to choose from, Europeans can pick from nine manufacturers offering CNG models, including American-owned Opel (General Motors) and Volvo (Ford) as well as Volkswagen, BMW and Mercedes.

Better still, the majority of their offerings are dual-fuel cars that can switch over to petrol if they run out of natural gas. Your correspondent thinks he has to find a way of importing one.