Honda VTEC vs. i-VTEC

If we look at the differences between VTEC vs. i-VTEC systems, which are vehicle systems, there is actually no significant difference. There is no difference between i-VTEC vs. VTEC system in terms of hardware or parts.

In old type VTEC vehicles, the VTEC system could only open VTEC based on engine speed. For example, the first VTECs could only open VTEC after 5500 rpm. Later, with the development of technology, VTEC can be opened at lower engine speeds, approximately 3000 rpm.

The fact that the engine can only open VTEC at 5500 rpm in a vehicle, this situation had a very negative effect on fuel consumption, as the engine had to turn much higher revolutions in order to get performance. Considering that the average engine speed band is 1500-4000 rpm when driving normally, VTEC was dysfunctional as performance was obtained at high engine speed bands that vehicle drivers generally could never get out of.

However, with the development of technology, the VTEC’s engagement band was reduced to around 3000 rpm in the next generation. This was normal for drivers, so VTECs became more common. But still, the VTEC system was not smart.

i-VTEC stands for intelligent, with the letter i at the beginning of the word. The i-VTEC system, on the other hand, thanks to its more advanced electronic equipment, can be used based on the power and torque needed at all engine speeds and in all conditions, regardless of any speed. This is the biggest difference between VTEC and i-VTEC.

Variable Valve Timing and Lift

Variable Valve Timing and Lift

VTEC vs. i-VTEC are two systems used by Honda engines to enhance performance, respectively. VTEC stands for Variable Timing Electronic Control.

VTEC made driving cars like the Civic Si and EX more exciting at higher engine speeds thanks to its original DOHC version, creating an enjoyable driving experience at high engine speeds. VTEC boosts power by altering camshaft timing and lift for intake and exhaust valves – an effective method of increasing engine torque and horsepower. For VTEC vs. i-VTEC, there are examples from many different units.

VTEC (variable valve timing and lift) is a system for controlling variable valve timing and lift. Camshafts on an engine’s intake and exhaust valves contain camlobes which press against rocker arms to open them when rotated; their shape determines timing, lift, duration of each valve. In general, inlet camshafts tend to open at lower rpm than exhaust ones to create smooth idle and good fuel economy when cruising.

VTEC vs. i-VTEC are two technologies implemented by Honda into their engines to enhance performance, each having distinct qualities yet sharing some similarities.

VTEC allows the engine to increase power at higher rpms by altering valve lift and timing, using a camshaft with variable-sized lobes.

Honda VTEC (variable Timing and Lift Electronic Control, or VTC for short) is an engine technology designed to enhance volumetric efficiency by altering the timing of intake and exhaust valves, enabling more fuel+air injection into higher RPM cylinders while still maintaining good low RPM torque levels. As an industry first, VTEC utilizes hydraulic systems to switch between various camshaft profiles. This is an important detail for VTEC vs. i-VTEC.

VTEC differs from i-VTEC by not just changing timing but also lifting. Every camshaft features two rocker arms, one controlling lower lift profile while another controls higher. When an ECU detects that engine RPM has exceeded certain levels, its rocker arm positions will change so the outer rockers shift up to raise the intake valve lift profile, opening more air+fuel for combustion at high RPM resulting in more power being generated at that speed. There are some differences in engine performance for VTEC vs. i-VTEC.

At low RPMs, the rocker arm moves in an opposite direction so that outer rocker arms move downward to reduce intake valve lift and close cylinders more rapidly for improved low RPM torque production. Once engine speed drops below its original value, however, it reverts back to its original position allowing gradual opening rates that maximize power and fuel economy at lower RPMs.

VTEC can boost RPM horsepower, but it doesn’t do much to improve low to mid range torque; thus i-VTEC was created. i-VTEC works alongside all the systems on your car to deliver optimal performance under all circumstances.

The i-VTEC system differs from VTEC in that it takes into account more than just camshaft positions and lift. Instead, this intelligent system can also adjust intake manifold height, fuel delivered via mass airflow sensor and engine coolant temperature to optimize performance under all circumstances. Thus, i-VTEC offers much greater intelligence than simply being another variation of VTEC.

Variable Valve Lift Electronic Control

Honda VTEC technology was one of the most successful internal combustion technologies ever introduced into production cars, becoming an icon during its introduction in the 1990s and still standing out today as a hallmark of their brand.

The original DOHC VTEC engine design became legendary for combining fuel economy and power in an unparalleled driving experience – VTEC engines are known for being quiet at low RPM until suddenly shifting onto their high lift profile to deliver instantaneous bursts of power when switching over from quiet mode into high lift mode – this dynamic makes VTEC engines such a favorite with drivers alike!

As a result, the engine can always optimize exhaust and inlet valve operation to deliver maximum power and fuel efficiency at all RPMs – an enormous benefit over traditional systems offering only a single camshaft profile. There are some important differences in transmission and suspension for VTEC vs. i-VTEC.

The i-VTEC system takes the VTEC concept one step further by adding a third rocker arm which keeps inlet valves open longer at lower throttle levels, making the engine efficient under 4500 rpm yet providing all of the zinging power of VTEC above that point.

Variable Valve Timing with Intelligence

Honda VTEC system has proven itself a revolutionary technology in motorsports and racing, but was initially created for very practical application: modern Japanese family sedans. VTEC was originally intended to deliver power across an expansive rpm/torque spectrum while remaining smooth and efficient at low rpm; VTEC solved both problems by permitting different modes to operate depending on engine conditions.

Honda’s variable valve timing system (VTEC) goes beyond traditional variable valve timing systems by also altering camshaft profiles and lift. This enables its engine to remain smooth at lower speeds while powerful at higher rpm by hydraulically switching between two or even three different camshaft profiles, changing both valve timing and lift simultaneously.

To gain an understanding of how this works, let’s examine the diagram. Each cylinder features its own set of cams with distinct profiles and lift. For instance, one cam may feature faster timing or higher lift than others to provide high rpm horsepower production; therefore it will open and close more frequently than its peers.

The two outer cams feature slower profiles and smaller lifts, opening and closing more slowly than their middle counterpart, but not quite as slowly as the first two cams. This provides excellent low-rpm torque as well as fuel efficiency.

Honda’s VTEC system optimizes power delivery throughout its entire rpm range by changing valve lift and timing at every rpm level, as well as switching seamlessly from high to low rpm mode without needing a cold start.

Finally, the recently introduced 3-stage i-VTEC system combines VTEC with Variable Timing Control (VTC), giving drivers more options than ever. All three functions can be managed simultaneously by an ECU that controls them all simultaneously – giving drivers even greater choice in how their vehicle drives.

Honda VTEC technology can be found in their most recent models such as the Civic Si and RSX Type-S. If you want to gain more knowledge of this system, Jason Fenske’s video provides an in-depth explanation. This is one of the most well-known examples, for VTEC vs. i-VTEC.


VTEC technology enhances performance by speeding airflow in and out of an engine, which increases power, acceleration, and efficiency while simultaneously increasing power and acceleration. Available on several Honda models including Civic Sedan EX/LX sedans as well as coupe LX models, CR-Vs, Odysseys and hybrid/fuel efficient vehicles alike – as well as offering fuel-efficient versions known as i-VTEC engines!

i-VTEC works similarly to VTEC in that it also modifies valve timing and lift, but on both intake and exhaust valves at once – this allows an engine to optimize both low-performance operation as well as high performance operation by continuously altering them; unlike prior camshaft designs which only activated at certain RPM ranges.

The i-VTEC mechanism does have some minor drawbacks, although they’re manageable. One of the intake cam-lobes may open more than its counterpart – this doesn’t impact overall system function and doesn’t change air/fuel ratios or fuel economy significantly. Furthermore, low RPM operation doesn’t cause intake valves to close automatically which reduces air-to-fuel ratios and decreases economy.

Since its introduction, Honda fans have long appreciated its VTEC engine as a staple for performance models from their lineup. Today, this engine can still be found everywhere from BR-Vs to SR-Vs in Honda models with VTEC engines.

VTEC vs. i-VTEC technologies offer drivers a great way to increase power while improving engine efficiency, offering unique benefits for each driver. No matter which model you opt for, both options are ideal choices for fast yet fuel-efficient vehicle driving experiences; simply do your research on both technologies before making a choice that’s appropriate for you and your lifestyle/budget.

There are two different varieties of i-VTEC engine, the former designed for performance engines such as those found in Honda Integra RSX Type S and Civic Si, while the latter one serves economy applications such as those seen on Accord and Civic models.

Juan Gibson

Juan is an automotive engineer and an avid car enthusiast. He has over 15 years of experience in the car industry. In my free time, I write blog posts about cars, models and etc.

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