Today gasoline is pretty much the standard universal car fuel. In the future can we have one system like this or will we be forced to have many parallel systems?

Hydrogen or bio-buthanol most likely. I think a one or two-fuel system will be the future's fuel

More than likely hydrogen and/or bio alcohol fuels would be king of the future's fuels.

It is going to be tough to have several parralel systems.

It is going to be tough to have several parralel systems.

It depends on the actual design of the system. If the designs are similar enough a compromise between the two designs may be possible allowing for one system compatible with different fuels. Or even a relatively simple mode change to set the system to work with the new fuel.

People have proposed using Hydrogen as a fuel for a more typical internal combustible engine. However fuel cells (which are drastically different from internal combustion) are not compatible with an internal combustion design in this manner due to the radical difference in design. So a parallel system would be required for a Internal combustion + Hydrogen Fuel cell design.

It is going to be tough to have several parralel systems.

Why?

We already are running parallel systems. In the USA, diesel, unleaded, and K-1 are commonly distributed at the same filling stations. We have trains that switch from third rail to overhead wire to diesel - all without changing the locomotive.

Parallel systems are all around us already. The reason we don't notice it is because they work so seamlessly.

Horses. :mischief:

Electric cars and hydrogen cells.

Biofuels are okay for short-term, not for long-term.