Here are some alternatives to petrol for powering cars:

Electricity:

Battery Electric Vehicles (BEVs): These cars run entirely on electricity stored in batteries. They are charged via electric outlets or charging stations.

Pros: Zero tailpipe emissions, lower operating costs, quieter operation.
Cons: Limited range compared to petrol, longer refueling time, dependence on charging infrastructure.

Hydrogen:

Fuel Cell Electric Vehicles (FCEVs): These cars use hydrogen to generate electricity through a fuel cell, which powers an electric motor.

Pros: Zero emissions (only water vapor), relatively fast refueling, long range.
Cons: High production costs, limited refueling infrastructure, hydrogen production can be energy-intensive.

Natural Gas:

Compressed Natural Gas (CNG) Vehicles: These cars use compressed natural gas stored in high-pressure tanks.
Pros: Lower emissions compared to petrol and diesel, often cheaper fuel.
Cons: Limited refueling stations and reduced cargo space due to storage tanks.

Liquefied Petroleum Gas (LPG):

Autogas Vehicles: These cars run on LPG, a mixture of propane and butane.
Pros: Lower emissions than petrol and diesel, often less expensive.
Cons: Reduced energy density, limited refueling infrastructure, less power compared to petrol.

Biofuels:

Ethanol: Made from plant materials, ethanol can be used in blends with petrol (e.g., E85 contains 85% ethanol).
Biodiesel: Produced from vegetable oils or animal fats, biodiesel can be used in diesel engines (e.g., B20 contains 20% biodiesel).
Pros: Renewable sources can reduce greenhouse gas emissions.
Cons: Limited availability may affect food supply and land use.

Hybrid Systems:

Hybrid Electric Vehicles (HEVs): Combine a petrol engine with an electric motor to improve fuel efficiency and reduce emissions.

Plug-in Hybrid Electric Vehicles (PHEVs): These can be charged from an external source and run on electricity for short distances, switching to petrol for longer trips.

Pros: Flexible range, reduced fuel consumption.
Cons: The complexity of dual power systems results in a higher initial cost.

Synthetic Fuels:

E-Fuels: Produced from renewable electricity and CO₂, these can be used in traditional internal combustion engines.

Pros: Can be used with existing infrastructure and engines, potentially lowering lifecycle emissions.
Cons: Still in development stages, currently expensive to produce.

Each of these alternatives has its own set of benefits and challenges, and their viability can vary based on regional infrastructure, technological advancements, and environmental policies.