Dual VVT-i Technology in Car Engines

Dual VVT-i Technology in Car Engines Dual VVT-i is an advanced technology applied to internal combustion engines to improve fuel efficiency, engine performance, and reduce exhaust emissions. This technology was developed by Toyota and is an evolution of the VVT-i (Variable Valve Timing with intelligence) system, which Toyota first introduced in 1996.

In general, the VVT-i technology functions to adjust the timing of the opening and closing of the engine’s valves (valve timing) variably, both for the intake and exhaust valves, according to the engine’s conditions and speed. The aim is to optimize combustion efficiency and engine performance, which in turn increases power output and fuel economy.

Explanation of Dual VVT-i

VVT-i for Intake and Exhaust Valves
In engines equipped with Dual VVT-i, there are two separate valve timing adjustment systems: one for the intake valves and one for the exhaust valves. The term dual here refers to two separate VVT systems working simultaneously for both valve types.

Intake Valves: The VVT-i system for the intake valves adjusts the timing to allow more air into the combustion chamber at lower engine speeds and adjusts the timing at higher engine speeds to ensure more efficient combustion.
Exhaust Valves: The VVT-i system for the exhaust valves adjusts the timing to improve the expulsion of exhaust gases, making the combustion process more efficient and helping reduce harmful emissions.

Variable Valve Timing Intelligent

Causes of stuck wiper water

Coolant as radiator water

Benefits of Dual VVT-i

This technology offers several advantages, including better engine performance, improved fuel economy, and reduced exhaust emissions. Some key benefits of Dual VVT-i are:

Enhanced Engine Durability: Because the combustion process is more efficient and energy loss is minimized, pressure inside the combustion chamber is more stable, which can extend engine life.

Fuel Efficiency: By adjusting the timing of the valve opening and closing according to the engine’s needs at various speeds, the engine can operate more efficiently, utilizing fuel better. This reduces fuel consumption, especially at lower or medium engine speeds.

Improved Engine Performance: At higher engine speeds, the engine can take advantage of optimal valve timing to produce more power. This results in better acceleration and faster engine response.

Reduced Exhaust Emissions: By precisely controlling valve timing, combustion becomes more complete, which helps reduce harmful exhaust emissions such as NOx, CO, and hydrocarbons

How Dual VVT-i Works

The VVT-i system works by using a servo motor that adjusts the valve timing mechanism. The servo motor receives signals from the ECU (Engine Control Unit) based on various parameters such as engine speed, load, temperature, and other factors.

At low to medium engine speeds, the ECU adjusts the timing to open the intake valves earlier and wider to allow more air into the combustion chamber.
At high engine speeds, the ECU adjusts both the intake and exhaust valve timings to maximize combustion efficiency and power output.

Since both VVT-i systems work independently (for intake and exhaust valves), the engine can more flexibly regulate air and exhaust gas flow according to driving conditions.

Application in Cars

Dual VVT-i technology has been applied to various Toyota and Lexus models, including both 4-cylinder and 6-cylinder gasoline engines. For example, you can find this technology in models like the Toyota Corolla, Toyota Camry, and Toyota Hilux, where it enhances the vehicle’s performance and fuel efficiency.

Dual VVT-i is a highly beneficial technology that meets the demands for better fuel efficiency, more responsive performance, and reduced exhaust emissions. By adjusting the timing of both the intake and exhaust valves separately, the engine can work optimally under different driving conditions, making it more efficient and environmentally friendly. This technology is a prime example of how automotive innovations continue to improve the driving experience while supporting the need for vehicles that are more energy-efficient and eco-friendly.