Cars can and do run on alcohol.
An example of cars running on alcohol is the ethanol that is added to gasoline which is an alcohol that powers many cars and other gasoline vehicles today.
Flexible fuel vehicles can run on 85 percent alcohol or ethanol and even early gasoline powered engines can be adapted to run on alcohol.
Ethanol is a type of alcohol which is used as a fuel and it's actually commonly blended with gasoline that we use today in various proportions.
E10 is a blend of 10 percent ethanol and 90 percent gasoline and is widely available and also compatible with many modern gasoline engines.
E85 is a blend of 85 percent ethanol and 15 percent gasoline and requires specially designed vehicles and they are also known as flexible fuel vehicles.
Flexible fuel vehicles are equipped to run on a range of ethanol concentrations which include E85 without causing damage to the engine.
Alcohol fuel also has a history in use in internal combustion gasoline engines and early engines were designed to run on ethanol.
A car can also run on water but not directly.
A car cannot run on the water alone although the water can be used to make and produce hydrogen gas through a process called electrolysis.
The hydrogen gas that is extracted from the water through electrolysis is what is then burned to power the car.
Water itself is not a fuel as water molecules also known as H2O are chemically stable and don't burn readily like gasoline or other fuels do.
In order to use the water as a fuel source for the cars engine you first have to extract the hydrogen gas from the water through electrolysis.
The electrolysis process to extract the hydrogen gas from the water requires a significant amount of electrical energy so it's not feasible or practical to use water to run a car.
The amount of energy that is required to extract the hydrogen gas from the water to power the car is more than the energy that you would get back from burning it so it would be very inefficient to run a car on water.
The way a water powered car in concept would work is that the water would be split into hydrogen and oxygen gases through the process of electrolysis which uses electricity to break the molecules in the water down.
The hydrogen gas once extracted from the water could then be burned in a combustion engine or used in fuel cells to produce electricity that can power the car.
Some concepts also involve the use of a hybrid system in which the car runs primarily on gasoline but also has a small electrolysis system to supplement the fuel with the hydrogen.