What does a dual VVT engine mean?

[StJayla]

Dual VVT engine refers to the VVT-i engine, which is the English abbreviation for Toyota's intelligent variable valve timing system. The following is an introduction to dual VVT engines: 1. The function of VVT engines: Most valve timing systems on the market can achieve stepless adjustment of the intake valve timing within a certain range. Some engines are also equipped with a VVT system on the exhaust valve, thereby achieving stepless adjustment of valve timing on both the intake and exhaust valves (i.e., D-VVT, dual VVT technology), further optimizing combustion efficiency. 2. The principle of VVT engines: Variable valve timing technology also improves power performance by changing the intake air volume, but valve timing can only advance or delay the valve opening time and cannot effectively improve the intake air volume per unit time in the cylinder, so its assistance to engine power is limited.