What kinds of small car engines are there? What does yaris's dual VVT engine mean?

There are many kinds of engines. I don't know what kind of classification you are talking about, but there is no difference between a small car and a large car.

VVT is a widely used engine technology called variable valve timing.

VVT-I is Toyota's unique variable valve technology, which is called intelligent variable valve timing. The principle of action is to use the driving computer to change the opening and closing time of the throttle valve, effectively control the air intake, and let the engine cylinder inhale more air, so as to realize full combustion in the cylinder, increase work, and make the car have greater torque and power, stronger acceleration and faster driving speed; Therefore, the reverse action can reduce the fuel injection and achieve the purpose of fuel saving under the condition of ensuring normal torque and power.

Double VVT-I refers to the use of intelligent variable technology on the intake valve and the same technology on the exhaust valve, so that the engine can exhaust exhaust exhaust gas in advance in the exhaust stroke and the cylinder is in a sub-vacuum state. When entering the intake stroke, more air is sucked into the cylinder by using the air pressure difference inside and outside the cylinder, thus making the next work more powerful.