Typically, most cars use 4-stroke internal combustion gasoline engines. They range from 3 cylinders to 12 cylinders.
Some of these are supercharged and turbo-charged. There are normally water-cooled. These engines are commonly used in private vehicle and sport cars. Some of these engines can be modified to use propane.
There is also the Wankel engine or rotary gasoline engines too. It is a variation of the 4-stroke engine. The Mazda RX-7 uses this. It is compact and sporty.
There is another class of cars called the hybrids. These cars have both gasoline internal combustion engines and electric motors. The electric motors get their energy from batteries. These batteries get their energy from generators that convert the kinetic energy of the moving vehicle to electrical energy. Transfer of kinetic energy to electrical energy happens during the braking phase.
Another type of engine used in automotive application is the diesel engine. In the US the majority of these are found in commercial trucks and buses. Only about 1% of private cars use these engines in the US. As for the rest of the world, diesel engines are in about 11% of the cars. Most commercial vehicles in the world use diesel engines too. These engines can be turbo-charged and super-charged too for better efficiency. These engines last longer and is more reliable than gasoline engines. Diesel engines can also be converted to consume other fuels such as vegetable oil and used cooking oils.
However, diesel engines are not normally used in sport cars, and aircraft engines due to the low power to weight ratio. These engines are well suited for heavy marine vessels and railroad locomotives.
Normally, all these engines have at least one 12 volt battery.
This battery get its energy from the generator which in turn get it's energy from the mechanical energy of the engine when the engine is running.