The increase in oil prices allows nicely to highlight the mechanics of substitution. The increase in the price of most goods lead to a decrease in its use, while increasing the demand for its substitutes. This leads to an increase in the price in the other goods. We have seen this in the past month nicely with increases in electricity and food prices, although these are not pure substitution effects (oil is at least partly an input).
Another substitution effect come form the use of goods that were not used before. In the case of energy, using alternatives like solar energy or windmills becomes more economical, thus creating goods that were not in demand before. But again, this is not a pure substitution effect, because these alternative energy sources have been pushed for other reasons as well, such as pollution reduction.
For automobiles, the rise of hybrid cars is a substitution effect, although they still use some gas. What about a car that does not use energy from oil at all? Enter the AirCar, which simply runs on compressed air. The concept is ten years old, but was not economical until now (except for some cars running in Spain). Tata Motors, the major Indian car manufacturer now announced it will start producing a car based on this concept in August 2008. The MiniCAT will have a range of 300km for a maximum speed of 105km/h, the refill will come to $2.00 at a station, and an emergency compressor can be plugged into a socket to refill as well.
Note that this car does not use the air pressure per se, but rather the thermodynamic effect when you change the pressure and the volume of the air. The emissions are thus only very cold air, which can be used for air conditioning...