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VVT-i
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<p>VVT-i, or Variable Valve Timing with intelligence, is an <a href="/facts/Automobile/I1IsH8IK">automobile</a> <a href="/facts/Variable_valve_timing/Dcff7UBg">variable valve timing</a> <a href="/facts/Petrol_engine/oj3XzkQU">petrol engine</a> <a href="/facts/Technology/9Uav5WVR">technology</a> manufactured by <a href="/facts/Toyota_Group/WFqQ9q5L">Toyota Group</a> and used by <a href="/facts/Brand/hP6SnDWU">brands</a> <a href="/facts/Groupe_PSA/WFw49Uyq">Groupe PSA</a> (<a href="/facts/Peugeot/Y7M6sq1D">Peugeot</a> and <a href="/facts/Citroen/cF96vY9S">Citroen</a>), <a href="/facts/Toyota/wHIb40oG">Toyota</a>, <a href="/facts/Lexus/j6nKkWN8">Lexus</a>, <a href="/facts/Scion_(automobile)/JSy15VUC">Scion</a>, <a href="/facts/Daihatsu/RLJRDTBJ">Daihatsu</a>, <a href="/facts/Subaru/TcrHcYdq">Subaru</a>, <a href="/facts/Aston_Martin/eePWNngz">Aston Martin</a>, <a href="/facts/Pontiac_(automobile)/xuyM6f5Q">Pontiac</a> and <a href="/facts/Lotus_Cars/KkwYsc0f">Lotus Cars</a>. It was introduced in 1995 with the <i><a href="/facts/Toyota_JZ_engine/8or13Pkj">2JZ-GE</a></i> engine found in the <a href="/facts/Toyota_Crown_(S150)/Kl4WwFxB">JZS155 Toyota Crown</a> and <a href="/facts/Toyota_Crown_Majesta_(S150)/EutUX3km">Crown Majesta</a>. </p><p>The VVT-i system replaces the Toyota VVT system introduced in 1991 with the five-valve per cylinder <i><a href="/facts/Toyota_A_engine/xfaUJMHl">4A-GE</a></i> "Silver Top" engine found in the <a href="/facts/Toyota_Corolla_Levin_(E100)/5a47w2Jm">AE101 Corolla Levin</a> and <a href="/facts/Toyota_Sprinter_Trueno_(E100)/5a47w2Jm">Sprinter Trueno</a>. The previous VVT system was a 2-stage hydraulically controlled cam phasing system. </p><p>VVT-i varies the timing of the <a href="/facts/Intake/JPa4RTCy">intake</a> <a href="/facts/Poppet_valve/ADRB6Evc">valves</a> by adjusting the relationship between the <a href="/facts/Camshaft/qS8BWXVr">camshaft</a> drive (belt or chain) and intake camshaft. Engine oil pressure is applied to an actuator to adjust the camshaft position. Adjustments in the overlap time between the exhaust valve closing and intake valve opening result in improved engine efficiency. </p><p>Variants of the system, including VVTL-i, Dual VVT-i, VVT-iE, VVT-iW and Valvematic have followed. <a href="/facts/Direct_fuel_injection/0u4SxFyG">Direct injection</a> systems such as the D-4 (VVT-i D-4) and D-4S are also used in conjunction with VVT-i. </p>