VVT-i, or Variable Valve Timing with intelligence, is an automobile variable valve timing technology developed by Toyota. The Toyota VVT-i system replaces the Toyota VVT offered starting in 1991 on the 4A-GE 20-Valve engine. The VVT system is a 2-stage hydraulically controlled cam phasing system.
TOYOTA’s Variable Valve Timing with Intelligence engines use advanced computer technology to vary air intake according to driving conditions and engine load. By adjusting the overlap time between the exhaust valve closing and intake valve opening the engine can be tuned to provide instant engine torque across the entire rev range.
VVT-i brings substantial advantages in 3 main areas:
# It allows sporty performance.
# Reduces your petrol costs.
# More complete fuel burn at higher temperatures leads to fewer harmful emissions.
VVT-i, introduced in 1996, varies the timing of the intake valves by adjusting the relationship between the camshaft drive (belt, scissor-gear or chain) and intake camshaft. Engine oil pressure is applied to an actuator to adjust the camshaft position. In 1998, "Dual" VVT-i (adjusts both intake and exhaust camshafts) was first introduced in the RS200 Altezza's 3S-GE engine. Dual VVT-i is also found in Toyota's new generation V6 engine, the 3.5L 2GR-FE V6. This engine can be found in the AVALON, RAV-4, and CAMRY in the US, the AURION in Australia, and various models in Japan, including the ESTIMA. Other Dual VVT-i engines include the upcoming 1.8L 2ZR-FE I4, which will see implementation in TOYOTA's next generation of compact vehicles. By adjusting the valve timing, engine start and stop occur virtually unnoticeable at minimum compression, and fast heating of the catalytic converter to its light-off temperature is possible, thereby reducing HC emissions considerably.
TOYOTA’s Variable Valve Timing with Intelligence engines use advanced computer technology to vary air intake according to driving conditions and engine load. By adjusting the overlap time between the exhaust valve closing and intake valve opening the engine can be tuned to provide instant engine torque across the entire rev range.
VVT-i brings substantial advantages in 3 main areas:
# It allows sporty performance.
# Reduces your petrol costs.
# More complete fuel burn at higher temperatures leads to fewer harmful emissions.
VVT-i, introduced in 1996, varies the timing of the intake valves by adjusting the relationship between the camshaft drive (belt, scissor-gear or chain) and intake camshaft. Engine oil pressure is applied to an actuator to adjust the camshaft position. In 1998, "Dual" VVT-i (adjusts both intake and exhaust camshafts) was first introduced in the RS200 Altezza's 3S-GE engine. Dual VVT-i is also found in Toyota's new generation V6 engine, the 3.5L 2GR-FE V6. This engine can be found in the AVALON, RAV-4, and CAMRY in the US, the AURION in Australia, and various models in Japan, including the ESTIMA. Other Dual VVT-i engines include the upcoming 1.8L 2ZR-FE I4, which will see implementation in TOYOTA's next generation of compact vehicles. By adjusting the valve timing, engine start and stop occur virtually unnoticeable at minimum compression, and fast heating of the catalytic converter to its light-off temperature is possible, thereby reducing HC emissions considerably.
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