What could replace the oil and petrol in future cars?

Many attempts have been made to find an alternative for petrol. There are many variants, from using hydrogen, natural gas, methanol or other fuels. The most important obstacle is the price of these fuels as well as the price of the cars that can use them. Many scientists think that fuel can easily be obtained from the organic matter and crops. Some of the crops, such as maize and wheat can be used to extract oil and produce biodiesel. Sugar from the sugar canes is also a good solution. Methanol and ethanol that is produced from the fruit and vegetables can also be used as fuel for future vehicles. Now petrol is still abundant and there is no need to think about the new solutions, but for the future generations, it will be very important to use new and environmentally friendly alternatives to petrol.