The futuristic ''concept cars'' at the Tokyo auto show are taking on an all-too-real immediacy this year amid soaring oil prices, with ecologically-friendly autos grabbing the limelight. The overriding message at the Tokyo Motor Show, which opens Saturday, is that gas-guzzlers must make way for green cars that pollute less and rely less on shrinking supplies of fossil fuels.

The show's offerings include experimental ecological cars galore, including a vehicle that switches back and forth between an electric motor and a hydrogen-powered engine from Mazda and a small fuel cell car from Suzuki.