Where Are the Multi-Fuel Vehicles?

siena-tetrafuel-1.jpg

The Fiat Siena Tetrafuel can run on gasoline, ethanol, blends of gasoline and ethanol, and also natural gas. Is your next car going to be a multi-fuel? Photo: Fiat Brazil

A recent New York Times story describes the efforts of billionaire oilman T. Boone Pickens to promote alternative energy, including wind and natural gas. What caught my attention was the beginning of the story, which says demand for natural gas cars like the Honda Civic GX is running high in certain corners of the United States where that fuel has become an attractive alternative to pricey gasoline.

This is interesting because consumers have long been dismissive of natural gas vehicles. The main problem is a lack of natural gas filling stations (there are only about 1,600 in the U.S.). And then thereâ''s range. Natural gas vehicles have around half the range of comparable gasoline cars. (See other pros and cons here.) These issues have discouraged consumers and automakers alike. The Times reports that Honda plans to produce just 2,000 Civic GX units this year; Ford and GM donâ''t even have natural gas cars to offer.

What puzzles me is the this-or-that fuel approach. You can either run on gasoline or natural gas. Why aren't automakers offering cars designed to run on both?

Note the emphasis on designed. Sure, retrofitted vehicles that can burn gasoline and natural gas have been around for decades. But where are the truly multi-fuel automobiles for the masses?

The beauty of such vehicles is they help solve one of todayâ''s biggest energy problems: uncertainty. With fuel prices oscillating wildly, is it better to stick with gasoline, invest in a natural gas vehicle, buy a hybrid, or what? Who knows? Thatâ''s why multi-fuel is interesting. You fill up with whatever fuel is cheaper, or available, where you live. It's no silver bullet for the energy crisis, sure, but it just makes sense in places where more than one fuel is available. The point is multi-fuel could work as a bridge from petroleum to other possible technologies and fuels, be it batteries, hydrogen, cellulosic ethanol, whatever.

siena-tetrafuel-2.jpg

siena-tetrafuel-3.jpg

Last year, I wrote about one such multi-fuel vehicle, the Siena Tetrafuel, created by Fiat in Brazil. This car can run on pure gasoline, pure ethanol, blends of gas and ethanol in any proportion, and also natural gas. It will burn the natural gas -- the cheapest car fuel in Brazil -- while cruising, and it will switch on the fly to the liquid fuel mix whenever it needs more power. From the article:

And hereâ''s the best part: you can put any mixture of gasoline and ethanol into its tank -- from 100 percent gasoline and no ethanol to 100 percent ethanol and no gasoline. The engine automatically adjusts its ignition timing and the quantity of fuel injected into the cylinders on each cycle to get the most power out of whatever mixture youâ''ve got while keeping emissions under control.

Cars that can use different mixes of gasoline and alcohol have been around for years. And vehicles that let the driver switch between natural gas and gasoline arenâ''t new, either. But one car that can do both -- switching automatically between the fuels and adjusting its engine to suit an arbitrary gasoline-alcohol mix -- thatâ''s very new indeed.

In other words, Fiat engineers designed the Tetrafuel engine -- and programmed its engine control unit -- to operate optimally for all those fuels. Not your usual retrofit. Its multi-fuel capability eliminates the two main problems of natural gas-only vehicles. Canâ''t find a filling station with natural gas? Just use gasoline or ethanol. And with both gas and natural gas tanks, range is not a problem anymore.

Fiat's Brazilian subsidiary unveiled the Siena Tetrafuel almost two years ago. It expected to sell 2,500 units in 2007; it sold more than 10,000. This year it has sold nearly 6,000 so far. In terms of annual sales, the Tetrafuel should represent less than 1 percent of all flex cars sold in Brazil (flex cars can use both gasoline and ethanol; 1.7 million were sold last year). Itâ''s still a tiny market. But for Fiat -- and Brazilians -- itâ''s nice to have such option around in case oil prices skyrocket or something. It's all about flexibility. (In fact, gas prices oscillations and the availability of ethanol at filling stations led to an automotive revolution in Brazil; sales of flex cars went from virtually nothing in 2003 to about 90 percent of all new cars sold last year, when the Brazilian auto industry saw all-time record sales.)

So back to the original question: Why arenâ''t other automakers considering multi-fuel? Well, in a sense they are. There are a number of projects around. BMW has shown off a gasoline-hydrogen luxury sedan. Volvo developed a prototype that runs on gasoline, E85, natural gas, hythane, and biomethane. Most of these projects, however, don't involve mass-produced, affordable vehicles. Automakers say developing multi-fuel vehicles require a lot of R&D and the cars will need extra parts like separate tanks, sensors, and so forth, making the vehicles expensive. But how expensive? Fiat, for example, did a good job in keeping the Siena Tetrafuel's price tag low enough. In Brazil -- the only place where the car is available -- it costs about the same as a regular Honda Fit.

I guess in the end automakers will regard multi-fuel as a niche, too small of a market to bother. They appear to be seeking the â''next big thingâ'' that will take them out of the hole they find themselves in. But then again, as uncertainty about energy prices and availability mount, it appears that betting on a single fuel is a bad bet. We need more omnivorous vehicles.

Advertisement

Tech Talk

IEEE Spectrum’s general technology blog, featuring news, analysis, and opinions about engineering, consumer electronics, and technology and society, from the editorial staff and freelance contributors.

Newsletter Sign Up

Sign up for the Tech Alert newsletter and receive ground-breaking technology and science news from IEEE Spectrum every Thursday.

Advertisement