i-VTEC is an acronym for intelligent-VTEC – a technology that allows cars to behave differently at different engine speeds, by actuating different cam lobes at different speeds.

Now, in English that would mean: this stuff is good for your car.

VTEC or Variable Timing Electronic Control really stands for Variable valve Timing and lift Electronic Control. The ‘i’ in iVTEC stands for intelligent.

Picture say what a thousand words can’t – and a thousand pictures just explains it beautifully. So, here is what iVTEC really is:

History of iVTEC

iVTEC was invented and implemented by Honda, and Ikuo Kajitani a.k.a the Father of VTEC, an engineer in the First Design Dept at Honda’s Tochigi R&D Centre, designed this revolutionary VTEC engine technology.

The VTEC system has been around since 1989, first introduced on a 1.6 liter dual over-head cam (DOHC) engine in a Honda Integra. These engines have a separate camshaft for the intake and exhaust cam, and the VTEC changes the profile of both camshafts at the same time. And that was the beauty of VTEC when it came out, this use of two camshafts.

Further Progress:

Later, Honda started introducing VTEC also in single cam (SOHC) engines (i.e with a single camshaft for both intake and exhaust). The downside of this is that the VTEC system on these engines only work on the intake valves.

VTEC makes an incredible difference in engine performance. Well, an ideal car would not use a camshaft at all – it would use electric motors to open and close the valves at exactly the right time. However, with the abuse that an internal combustion engine gets, that’s not really an option. The next best thing is to have one cam-shaft for low revs, and one for high revs, and that’s exactly what VTEC does. A VTEC camshaft has two sets of lobes on the shaft.

Next Stage:

A 3-stage VTEC system, which combines the regular VTEC system for performance with the VTEC-E system for frugality at low RPM. Finally, from VTEC-E came i-VTEC. I for Intelligent.

Difference between VTEC and i-VTEC:

Increased performance is one advantage of the i-VTEC system. The torque curve is “flatter” and does not exhibit any dips in torque that previous VTEC engines had without variable camshaft timing. Horsepower output is up and so is fuel economy. Optimizing combustion with high swirl induction makes these engines even more efficient.

Also, one unnoticed but major advantage of i-VTEC is the reduction in engine missions.

iVTEC is good for the environment as well!

High swirl intake and better combustion allows more precise air-fuel ratio control. This  results in substantially reduced emissions.

Exhaust gases are now retained in the cylinder when necessary by changing camshaft timing. This also reduces emissions without hindering performance.

Honda is reaping benefits of its commitment, and still manages to stay on the tough hence fruitful fuel-efficient, environment-friendly road. Nice.