VVT

Definition

Variable Valve Timing (VVT) is a technology used in internal combustion engines that allows for the adjustment of the timing of the opening and closing of the engine's intake and exhaust valves. This technology optimizes engine performance and efficiency by altering valve timing based on various factors such as engine speed, load, and temperature, leading to improved fuel economy and reduced emissions.

5 Must Know Facts For Your Next Test

1. VVT systems can enhance engine performance across different RPM ranges, providing more power when needed and improving efficiency at lower speeds.
2. There are several types of VVT technologies, including VTEC (Variable Valve Timing and Lift Electronic Control) from Honda and VVT-i (Variable Valve Timing with intelligence) from Toyota.
3. By optimizing valve timing, VVT helps to reduce harmful emissions by ensuring a more complete combustion process.
4. VVT can contribute to better throttle response and drivability due to its ability to adjust valve timing in real-time based on driving conditions.
5. The implementation of VVT often leads to lighter engine designs as it allows for smaller displacement engines to perform comparably to larger ones.

Review Questions

• How does Variable Valve Timing improve engine performance compared to fixed valve timing systems?
  • Variable Valve Timing improves engine performance by allowing the engine to adjust valve timing according to various conditions like speed and load. This adaptability means that at low RPMs, the engine can optimize for efficiency, while at high RPMs, it can enhance power output. In contrast, fixed valve timing systems do not offer this flexibility, resulting in suboptimal performance across different driving scenarios.
• What are the environmental benefits of using Variable Valve Timing in modern engines?
  • Using Variable Valve Timing in modern engines provides significant environmental benefits by reducing harmful emissions. By optimizing the timing of valve operations, VVT ensures more complete combustion of fuel, which leads to lower unburned hydrocarbons and nitrogen oxides released into the atmosphere. Additionally, enhanced fuel efficiency results in less fuel consumption overall, further contributing to reduced greenhouse gas emissions.
• Evaluate the impact of VVT technology on automotive design and consumer preferences in recent years.
  • The impact of VVT technology on automotive design has been profound, leading manufacturers to develop smaller, more efficient engines without sacrificing performance. As consumers become increasingly conscious of fuel economy and environmental issues, vehicles equipped with VVT have become more appealing due to their enhanced efficiency and lower emissions. This shift has prompted automakers to prioritize VVT integration in their designs, influencing market trends toward greener technology and better overall vehicle performance.

Related terms

Camshaft: A rotating shaft that controls the timing of valve openings and closings in an engine.

Fuel Efficiency: A measure of how effectively an engine converts fuel into energy, typically expressed in miles per gallon (MPG) or liters per 100 kilometers (L/100 km).

Turbocharging: A process that uses a turbine-driven forced induction system to increase an engine's power output by compressing incoming air.