ALERNATIVE FUELS such as natural gas, gro- pane and methanol are be- ing offered as a solution to harmful automobile emis- sions, but many scientists believe these fuels are only temporary steps towards the ultimate fuel: hydrogen. Friday, August Mazda unveils its experimental station wagon Early metal-hydride storage tanks weighed up to kilograms, but Mazda's weighs just 250 kilograms fully fuelled and has a range of 200 kilometres in the HR-X. It can be refuelled approximately S00 times (each fill-up takes about fifteen minutes), giving the storage tank a lifespan of 100,000 kilometres. That compares favorably with meu clectric vehicle batteries with half Greg Wilson AUTOMOTION When burned, hydrogen. pro- duces only a small amount of water vapor and traces of nitrogen oxides. In a fuel cell, it can be us- ed to produce clean electric power. Fossil fuels, on the other hand, produce significant amounts of carbon dioxide, the “greenhouse” gas, as well as harmful pollutants such as carbon monoxide, nitrogen dioxides, and hydrocarbons. A number of automobile com- panies have been exverimenting with hydrogen fuel, including BMW, Mercedes-Benz and Toyota.. Mazda, however, has taken a unique approach towards | producing a practical, affordable hydrogen-fuelled automobile. Last October, Mazda Motor Corporation introduced a_ tiny two-seat urban car, the HR-X, -fueled by pollution-free hydrogen © gas. And just last week, Mazda unveiled an experimental compact * station wagon using _ hydrogen . fuel: Both are powered by Maz- da’s exclusive rotary engine, which gives: them a distinct advantag over. other automakers. ‘The rotary engine. is ideally suited for hydrogen _use,’’ says ‘Mazda's . general ° manager of powertrain research, .. Toshiro Yagi: “‘In a conventional engine, highly flammable hydrogen tends to cause pre-ignition and backfir- ing.. However, in the ‘rotary engine, the intake chamber and combustion *