Why are the gasoline engines of hybrid cars with large displacement?

It's not what you said. First of all, the displacement of hybrid vehicles is small, such as 1.6, 1.8. But the key problem is that the cost of plug-in hybrid system is very high. If you install this system for an A-class car. Then the price will rise from 6.5438+10,000 to more than 6.5438+0.5 million. Will not be recognized by the market. So, it's a B-class car like a normal hybrid car. So for the B-class cars currently on the market, the displacement is generally 2.0. The power is about 120kW. Some cars are taller, such as the Passat version of 2.0T or the winning of Mondeo. Therefore, it is necessary to meet the power demand of B-class cars. The whole power output system must meet the requirements. So there is. The power of engine+motor should meet the requirements of vehicle running. The problem arises.

First of all, the basic energy of hybrid electric vehicle is gasoline engine, so the gasoline engine is too small to support the whole system.

Secondly, hybrid power saves fuel because when the engine works under normal conditions, the hybrid power system converts the excess energy of the engine into electric energy and stores it. Use it when you need it. In other words, the waste of energy is reduced and the efficiency is improved. But if the system has been working under high load, that is, all the output of the engine is supporting the car, then there will not be enough energy to store.

Thirdly, if the motor is too large, it will always rely on the motor when the car is running, and the energy of the motor comes from the gasoline engine, which means that part of the energy of the gasoline engine is converted from kinetic energy to electrical energy, and then into kinetic energy. That's a waste. It is better to use a gasoline engine than an electric motor.

Finally, the motor is too big, which means that the battery must be very big to drive. Charging the battery requires the work of the gasoline engine. This repeated conversion of energy leads to the decrease of energy utilization rate. Can not save energy.

So, when you know the principle of hybrid fuel economy, you will know why.

The key point is that the hybrid electric vehicle is a process of storing the excess energy generated by the engine and using it at the critical moment when the vehicle is running at low power. In other words, the motor consumes the excess energy of the engine. The motor should not be a burden to the engine. In this way, there is one more process of energy conversion. Efficiency is bound to decrease.

Finally, the cost of hybrid power system is high, and small displacement vehicles are generally not installed.