When you’re exploring engine technology, you’ve likely come across i-VTEC and VVTi. These systems have revolutionized the way engines operate, providing better performance, fuel efficiency, and reduced emissions. In this article, we’ll go into a brief explainer of what i-VTEC and VVTi are, examining how they function and the differences between the two.
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i-VTEC History
Back in the 1989, Honda introduced their Variable Valve Timing and Lift Electronic Control system, or VTEC with the launch of the B16A engine and the Integra XSi. This was a major advancement in engine performance, and it allowed for better fuel efficiency, more horsepower, and even smoother operation.
Fast forward a decade or so, and Honda’s next generation of VTEC, known as i-VTEC (Intelligent VTEC), was making its way into many of the Japanese manufacturer’s best-selling models. This update to VTEC brought in not only improved valve timing, but also new features like variable valve lift and a more sophisticated electronic control system. This new technology further enhanced engine performance, giving Honda’s vehicles even better fuel efficiency and increased power output.
VVTI History
Designed to replace the VVT system introduced in 1991, VVTi was first announced in 1995, with the first Japanese models receiving the technology a year later, while United States based buyers would have to wait until the 1998 Lexus LS 400 launched to get their hands on the technology (the 2000 Celica was the first Toyota-badged model in America to receive it)
i-VTEC and VVTI Technology Explained
i-VTEC Mechanism
i-VTEC works by varying the lift, duration, and timing of the intake and exhaust valves as the engine moves through the rev range. It ensures your engine runs efficiently, resulting in improved fuel economy and reduced emissions.
The main components of an i-VTEC system are the VTEC component and the VTC component. The Variable Valve Timing and Lift Electronic Control (VTEC) enables the engine to switch between two camshaft profiles – one for low-speed operation and another for high-speed operation. The Variable Timing Control (VTC) continuously adjusts the intake camshaft timing, working alongside VTEC to improve performance across the rpm range.
VVTi Mechanism
The VVTI technology utilises a system called the Hydraulic Control System, which adjusts the intake camshaft timing via an actuator mounted on the end of the intake camshaft. This actuator continuously modifies the camshaft angle in response to engine load and speed conditions, ensuring optimal valve overlap for efficient combustion.
I-VTEC vs VVTI Comparison
Performance
When it comes to performance, both i-VTEC and VVTi systems offer significant advantages over traditional engines. With i-VTEC, you’ll benefit from Honda’s innovative Variable Valve Timing technology, providing better low-end torque and high-end power. VVTI, on the other hand, is Toyota’s version of variable valve timing, featuring a more progressive adjustment of the valve timing to suit your driving needs.
In terms of responsiveness, i-VTEC engines tend to have a more aggressive “kick” at higher RPMs. This gives you an exciting driving experience. VVTi systems usually provide a smoother and more linear power delivery, making them more suited for daily driving situations.
Fuel Efficiency
i-VTEC engines are known for their ability to optimise fuel efficiency at lower RPMs (think city driving, etc.), thanks to the system’s intelligent camshaft switching. VVTi, on the other hand, aims to maximize fuel efficiency across the entire rev range. This is achieved by continuously adjusting the intake and exhaust valve timing. As a result, you’ll notice a more consistent level of fuel efficiency, whether you’re driving in the city or hitting the highway.
Reliability
Both VVTi and i-VTEC engines are known to be pretty bullet proof and reliable. Obviously, proper maintenance, like keeping up with oil changes and using quality fuel, plays a big part in how reliable an engine will be, but generally both Honda and Toyota’s engines are known to be more reliable than many of their competitors.
Conclusion
Both i-VTEC and VVTi systems have become a big part of their respective manufacturers’ vehicle lineups. They offer better performance and fuel efficiency, while still keeping the incredible reliability that Toyota and Honda have become so well known for.
