What's the difference between VVT, CVVT, DVVT and VVT-i engines?

Friend! You should know VVT (Variable Valve Timing) variable valve timing system. The system adjusts the phase of the engine cam through the equipped control and execution system, so that the opening and closing time of the valve changes with the change of the engine speed, thus improving the charging efficiency and increasing the engine power. The principle of VVT (Variable Valve Timing) technology is to adjust the intake (exhaust) amount, valve opening and closing time and angle according to the engine operation. It is to optimize the air intake and improve the combustion efficiency. Its advantages are fuel saving and high power boost ratio. The disadvantage is the lack of speed and torque in the middle section.

The VVT of Korean cars is based on the VVT-I of Toyota in Japan and the VTEC technology of Honda. However, compared with Toyota's VVT-I variable timing valve technology, VVT is only a variable valve technology and lacks timing technology, so VVT engine is indeed more fuel-efficient than ordinary engines, but not as fuel-efficient as Toyota and Honda cars of Japanese cars.

BMW has adopted this technology in the previous generation engines, such as Honda's VTEC, i-VTEC,; Toyota's vvt-I; Nissan's CVVT；; ; Mivik; Mitsubishi; Suzuki's VVT；; ; Modern VVT；; ; Kia's CVVT has gradually started to be used. Generally speaking, it is actually a technology with different names.

VVT - i

VVT means "variable valve timing" in Chinese. Because it is controlled by electronic control unit (ECU), Toyota has a nice Chinese name "Intelligent Variable Valve Timing System". The system mainly controls the camshaft of the intake valve, and has a small tail "I", which is the English code for "intake". These are the literal meanings of "vvt-I". VVT-I system is the abbreviation of Toyota Intelligent Variable Valve Timing System, which has been widely installed in the latest Toyota engine. Toyota's VVT-I system can continuously adjust the valve timing, but it cannot adjust the valve lift. Its working principle is that when the engine changes from low speed to high speed, the electronic computer will automatically apply oil pressure to the small turbine in the driving gear of the intake camshaft, so that the small turbine rotates at a certain angle relative to the gear housing under the pressure, and the camshaft rotates forward or backward within 60 degrees, thus changing the opening time of the intake valve and achieving the purpose of continuously adjusting the valve timing.