Honda’s variable valve timing and lift electronic control (VTEC®) helps an engine make usable power throughout its entire rpm range, for satisfying throttle response in all situations. Fuel efficiency36 and emissions performance are enhanced as well.
VTEC is an elegant engineering solution that solves a problem inherent in internal combustion engines:
Intake and exhaust valve-opening characteristics (timing, duration and lift) that work well for low-speed power production are extremely inefficient at high engine speeds, and vice versa.
VTEC solves this by using two different sets of cam lobes to operate the valves.
The profiles of each type of cam lobe alter the timing, duration and lift of the valves to optimize engine breathing for its particular engine speed.
A hydraulic system switches between the different cam lobes, controlled by engine electronics