What is the difference between dual CVTC and ECVT?
3 Answers
The differences between dual CVTC and ECVT are as follows: 1. Dual CVTC: Dual CVTC is a variable valve timing system, which is a technology used in automotive piston engines. The variable valve timing system consists of solenoid valves and variable camshaft phase adjusters. By adjusting the camshaft phase of the engine, the intake volume can change with the engine speed, thereby achieving optimal combustion efficiency and improving fuel economy. The variable valve timing system can not only change the opening and closing times of the intake and exhaust valves but also enhance power output to some extent. Its principle involves using hydraulic action to alter the angle between the camshaft synchronous timing belt pulley and the end of the camshaft, thus changing the valve timing angle. 2. ECVT: ECVT can only be used in motor-driven or hybrid vehicles and is not applicable to gasoline engines. It adjusts speed through the motor, features an all-gear structure, can withstand greater torque, and offers higher efficiency and faster speed.
The core differences between dual CVTC and EVTC lie in control logic and actuation methods. In my daily repair work with dual CVTC models like Nissan's HR engines, they use hydraulic systems to independently control intake and exhaust camshafts. The advantages are mature technology and lower maintenance costs, though with slightly slower response. Last year when replacing a hydraulic solenoid valve for a customer's Sylphy, sludge buildup caused idle instability. EVTC, however, employs electro-hydraulic control like Honda's Earth Dreams engines, where the ECU directly commands motors to drive oil pressure valves. Around 2,000 RPM you can clearly feel much better throttle response. But the electronic system demands higher wiring harness quality - I previously handled a Civic case throwing error codes due to aged wiring. Overall, dual CVTC wins in stability while EVTC excels in precision, though the latter's repair costs run about 15% higher.
As a long-time Honda owner who's driven three generations of their cars, I must say the EVTC feels noticeably smoother to drive. My old 2.4L Accord with mechanical VTEC only showed its power after 4,000 RPM, while the hybrid Accord I upgraded to with E-VTEC delivers an ice-like smoothness when the electric motor kicks in. My cousin's Corolla uses a dual CVTC system, and there's always this half-second throttle delay in city driving. I remember last year during a long road trip, his car showed significant power loss in high-altitude areas, whereas my EVTC's electronically controlled valve timing adjustment maintained nearly full power even when crossing 3,000-meter mountain passes. There's also quite a fuel economy difference - his 1.8L averages 7.2L/100km while my 2.0L hybrid only uses 5.3L. Though when it comes to durability, his eight-year-old car only needed oil changes, while my electronic system cost over 800 yuan when a sensor failed last time.
