Difference Between VTEC and VVT-i

Edited by Diffzy | Updated on: September 09, 2023

       

Difference Between VTEC and VVT-i

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Introduction

Like Apple and Android, Toyota and Honda also have their own set of fans dedicated to their work. There are many reasons why people may have their likes and dislikes towards Toyota and Honda like their body types, price ranges, models, features, etc. However, one of the pivotal reasons why these two have their dedicated set of fans is because they use different engine technologies namely VTEC and VVT-i. While these two types of engines may not be completely different from each other, they both have their own sets of strengths and weaknesses. 

If one is curious to know which technology came first, it’s the former – VVT-i that is older than VTEC. VVT-I is a technology developed by Toyota, which stands for Intelligent Variable Valve timing. Whereas, VTEC is a technology developed by Honda and stands for Intelligent Variable Valve Timing and Lift Electronic Control. 

VVT-i optimizes performance by adjusting the timing of the intake and exhaust valves, through a hydraulic mechanism, it adjusts the timing of the camshaft, which in flip adjusts the timing of the opening and ultimate of the valves. A VVT-i engine is understood for its gasoline and combustion performance and reduced emissions. 

A VTEC engine optimizes overall performance by adjusting the timing and lift of the consumption and exhaust valves through the timing and raising of the intake valves. Honda automobiles obtain excessive energy at excessive RPMs, all the while presenting desirable gasoline performance at low RPMs. Honda’s VTEC engine additionally functions as an electronic manage unit which, as the name indicates, controls the lifting of the valve for improved gasoline intake and reduced emissions. We will talk about the differences between VTEC and VVT-I in this article. 

VTEC vs. VVT-i

Toyota uses VVT-i generation, which is also known as Variable Valve Timing with Intelligence. The name on its own is a complete explanation of the technology and timing of the intake valve. For instance, if the valve was opened for 5 seconds, it's going to now open for 10 seconds after the VVTi has been engaged. Subsequently, Honda’s engineers came up with VTEC, additionally called Variable Valve Timing and lift electronic control with intelligence. Contrary to Toyota’s technology, Honda’s engine doesn’t simply trade the timing of the open valve, it also alters how deep the valve will open. For instance, if the valve opened about 4 mm, it's going to open at 8 mm at better revs. This technology will increase efficiency at low RPMs and gives a lot of extra energy at excessive RPMs than VVTi. 

So, in short, VVTi technology changes the valve timings, while VTEC technology changes the depth (or lift) and timing of valves. Also, it is important to add that VVTi essentially works on the intake valve, on the other hand, the VTEC alters both the intake and exhaust valves. 

Difference Between VTEC and VVT-i in Tabular Form

          Properties            VTEC               VVT-i
Developed By             Honda               Toyota
Launched              1983                 1996
Full Formintelligent-VTEC (Variable Valve Timing and Lift Electronic Control)Variable Valve Timing with intelligence
ProcessPhase changing are carried out by a computer-controlled, oil-driven adjustable cam gearEngine oil pressure is exerted to an actuator to adjust the camshaft position
PerformancePhasing is decided by means of a aggregate of engine load and rpm, starting from completely retarded at idle to particularly superior at complete throttle and low RPM.adjustments within the overlap time among the exhaust valve remaining and consumption valve establishing consequences in progressed engine efficiency.

What is VTEC?

VTEC (described as Variable Valve Timing & increase digital management, but stands for Valve Timing Electronically managed) is a machine superior with the useful resource of way of Honda to improve the volumetric performance of a 4-stroke inner combustion engine, ensuing in higher typical overall performance at immoderate RPM, and reduce fuel consumption at low RPM. The VTEC machine uses two (or occasionally 3) camshaft profiles and hydraulically selects among profiles. It was invented by Honda engineer Ikuo Kajitani. It is fairly distinctive from intelligent VVT (variable valve timing) systems which trade most effectively the valve timings and do not trade the camshaft profile or valve delivery in any way. 

The VTEC device gives the engine valve timing optimised for each low and high RPM operation. In fundamental form, the single cam lobe and follower/rocker arm of a traditional engine is replaced with a locking multi-element rocker arm and two cam profiles: one optimised for low-RPM stability and gasoline efficiency, and the alternative designed to maximise high-RPM electricity output. The switching operation between the 2 cam lobes is managed by way of the ECU which takes account of engine oil stress, engine temperature, vehicle pace, engine speed and throttle role. With the use of these inputs, the ECU is programmed to replace from the low elevate to the excessive raise cam lobes when favourable conditions are met. At the switch point, a solenoid is placed that lets in oil stress from a spool valve to perform a locking pin which binds the excessive RPM rocker arm to the low RPM ones. From this factor on, the valves open and close in line with the high-lift profile, which opens the valve in addition and for a longer time. The transfer-over factor is variable, between a minimum and maximum factor, and is decided by engine load. The transfer-down back from excessive to low RPM cams is about to arise at a decreased engine pace than the transfer-up (representing a hysteretic cycle) to avoid a scenario wherein the engine is asked to perform continuously at or around the switch-over point.

The older method of timing adjustments is to produce a camshaft with a valve timing profile this is better desirable to low-RPM operation. The upgrades in low-RPM performance, which is where maximum street-driven automobiles perform a majority of the time, arise in exchange for energy and efficiency loss at higher RPM levels. Correspondingly, VTEC tries to combine low-RPM gas efficiency and balance with high-RPM overall performance. 

Selling Points of the Honda VTEC System

VVT

Honda's VTEC, VTC and i-VTEC engines use a technique called VVT (short for Variable ValveTiming). 

Change the valve open time. When you press the accelerator pedal, the timing belt turns the camshaft, increasing your torque. 

Increased Horsepower

Perhaps one of the most favoured points of Honda'sVTEC system is that it is one of the most powerful engines in its class. 

The VTEC engine produces 160 kW @ 7,500 EPM and uses mechanical ventilation to increase airflow through cams that can be easily adjusted to different angles. 

Different Size Cams

Unlike conventional engines, VTEC Honda engines have a different camshaft. In an engine, the camshaft has many lobes of the same size. But the Honda engine is a little different because it has two smaller lobes and one larger area. 

The outer lobe will keep the valve open when running at low speed. However, as the engine starts to spin faster, the central cam will keep the valve open(or close it with the rocker's arm). 

This action, which usually provides better performance and acceleration, is called "VTECboot". 

Second Power Curve

An ordinary engine starts to lose power when it reaches the top of the RPM range, which slows it down and prevents it from reaching higher RPM. This situation has  been a complaint of car owners for a long time. However, Honda's VTEC technology provides second-order power which in turn allows the engine to release more power. 

Low Consumption of Fuel

With the help of  VTEC technology, less fuel gets burned as power passes through the intake and exhaust, providing the vehicle with the power it needs to run properly. This can reduce fuel consumption by great margins.

Reduced Emissions of CO2

Honda is all set to reduce its CO2 emissions by 20 from the 2020 milestone. This is done successfully with the VTEC system. By using the automatic timing valve, consumption of fuel is reduced while switching to higher power of the intake manifold. 

Driving in Adverse Conditions

On good roads, one may need to reduce their speed in order to avoid any damage to the vehicle. VTEC helps our vehicle to control the flow from high to low. 

This reduces fuel consumption and improves the vehicle's performance even in harsh conditions, allowing us to reach faster than we want. 

What is VVT-i?

VVT-i, also known as Variable Valve Timing Intelligent, is Toyota's name for its variable valve technology in most of its vehicles. 

Although the specifics of the system vary, it mixes the air-to-fuel ratio to the engine when the engine valve is opened and closed, depending on how the vehicle is driven. The majority of manufacturers use variable valve timing. This is done to cut down on emissions and maximize efficiency. A portion of the various valves likewise work on the fumes valve, which opens to eliminate the air-fuel combination from the motor.

With variable timing, the valves stay open for less time during gentle acceleration or idling, thus allowing less air-fuel mixture to enter the engine, helping to reduce emissions. During strong acceleration, the valves stay open longer, so more air-fuel mixture enters the engine and more power is produced. 

In Toyota's VVT-i, the electronic control valve (the "brain" that controls the operation of the engine) constantly calculates the best time to open and close the valves and open the fuel pressure. valve, change the timing by changing the camshaft speed. Some Toyota engines, such as the 3.5-litre V-6 in the Highlander SUV, use an electric motor to change valve timing, which Toyota labels VVT-iE (electric). 

The exhaust valve of the 3.5-litre and 2.5-litre engines used in the Camry sedan also has a different timing called Dual VVT-i. By optimizing time-based driving, Toyota says VVT-i can increase power, improve fuel economy and reduce emissions. 

Alfa Romeo was the first manufacturer to offer a timing differential in the 1980s, and others, including Honda with its VTEC system, followed suit in 1989. 

Toyota introduced the VVT-i in 1995 and introduced it to the United States with the redesigned 1998 Lexus LS 400. The 2000 Celica was the first Toyota model in the United States. Except for the Mirai fuel cell car, the 86 coupe, and the Supra sports car, all Toyota models currently sold in the US have VVT-i engines. The 86 was using a Subaru engine, the Supra was using a BMW engine, and both had different timing. 

Advantages of VVT-i Engines

VVT-i technology has been in use for over twenty years and one of its main benefits is its contribution to the performance of vehicles. It helps reduce emissions and combustion and is proven to be economical. The oil control valve, or OCV, continuously controls hydraulic pressure to advance and retard valve timing. 

The VVT-i is designed to be reliable and easy to adapt to existing engine models. VVT-i increases power and output, making the car more efficient. 

Disadvantages of VVT-i Engine

Some disadvantages of the VVT-i engine include higher maintenance costs. 

This process mostly depends on the oil pressure of the actuator. If the system does not operate due to dirt or mud, the system will stop. The system relies on a few things, and even the slightest glitch in these matters can annoy you and leave a big hole in your pocket. 

Main Difference Between VTEC and VVT-i in Points

  • VTEC is developed by Honda whereas VVT-i is developed by Toyota 
  • The VVTi only alters the timing while i-VTEC alters the timing as well as the lift of the valves. 
  • The VTEC makes changes to both, the intake and the exhaust valves. The VVTi technology on the other hand works only on the intake valve. 
  • VTEC was launched in 1983 whereas VVT-i was launched in 1996. 

Conclusion

To conclude, we can say that the i-VTEC engine by Honda is more powerful than its rival Toyota’s VVTi when it boils down to having more strength at high RPMs; it is also more cost-efficient at low RPMs like the VVTi tech. No engine is a complete winner here since both technologies are somewhat similar to one another if we keep aside some pivotal differences. 

We must also keep in mind that drivers have their likes, dislikes, and preferences when it comes to using one type of engine over another. 

References

  • https://blog.olx.com.pk/autos/the-battle-of-the-engines-toyotas-vvt-i-vs-hondas-i-vtec/
  • https://www.jdpower.com/cars/shopping-guides/what-is-a-vvt-i-engine
  • https://vinsautogroup.com.sg/why-is-the-honda-vtec-engine-so-pooular/

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"Difference Between VTEC and VVT-i." Diffzy.com, 2024. Fri. 23 Feb. 2024. <https://www.diffzy.com/article/difference-between-vtec-and-vvt-i>.



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