What is the difference between DOHC and DVVT?

[StJoseph]

The differences between DOHC and DVVT are as follows: 1. In terms of components: DOHC has two overhead camshafts placed on the cylinder block, one acting to drive the intake valves and the other to drive the exhaust valves. DVVT, on the other hand, employs dual continuous variable valve timing technology for both intake and exhaust. 2. In terms of environmental protection: The camshaft in DOHC is part of the engine's valve train, which ensures that the engine timely fills the cylinder with a new combustible air-fuel mixture during operation, improving emission efficiency. DVVT adjusts the air-fuel mixture in the engine's combustion chamber to achieve the most balanced fuel ratio, which helps improve the issue of car idle vibration, thereby enhancing the smoothness and comfort of the vehicle.