What Is VTEC? Honda's Underhood Tech Explained
Here's what happens when VTEC kicks in.
Honda
QuickTakes:
Combustion engines may seem like yesterday's news with flashy new electric vehicles on the road, but there's actually a lot of advanced technology, both computer-controlled and mechanical, that goes into a modern combustion engine. One of the best-known examples of that technology is Honda's variable valve timing and lift electronic control (VTEC).
What is Variable Valve Timing and Lift Electronic Control?
The VTEC acronym is a loose interpretation of the full name for Honda's innovative valve-timing system, the Variable Valve Timing and Lift Electronic Control system. VTEC was first added to Honda's engines in 1989.
In simple terms, VTEC makes it possible to have the benefits of an engine designed to make more power at higher engine speeds while also driving well around town and at low speeds.
Why Did Honda Invent VTEC?
Honda credits research and development engineer Ikuo Kajitani with inventing the VTEC system at Honda's Tochigi research and development facility in Japan. The motivation for the invention was a desire to solve the traditional shortcomings of small-displacement engines like those Honda used in its cars: high-revving, multivalve engines typically have very little low-rpm torque, but modifying the engine to regain that low-end torque comes at the expense of top-end power.
Instead, Kajitani designed a system that let Honda's engines effectively change out one set of compromises for the other on the fly — enabling the best of both worlds. The end result of this development process was VTEC.
Generations of VTEC
The earliest versions of VTEC offered two basic profiles: One optimized for low-rpm driving (i.e., optimized for efficiency) and the other for high-rpm driving (i.e., optimized for power). When the VTEC system transitioned from the low-rpm to the high-rpm mode, there was a corresponding surge in power that felt not unlike a turbocharger or other power-adding device. It's this characteristic that inspired legions of car kids to wax rhapsodic about the moment VTEC "kicked in." This generation of VTEC was available initially on the Integra, but was eventually available on almost all of Honda's cars.
VTEC-E was one of the first advances on the VTEC theme. It was introduced in 1992, with a focus on improving efficiency exclusively; VTEC-E enabled the 1992 Civic VX to reach 39/49/43 mpg city/highway/combined.
By the early 2000s Honda was ready for the next step in the VTEC's evolution: i-VTEC. The "i" in i-VTEC stands for intelligent because it incorporates additional features and better computer integration.
For the four-cylinder engine, Honda combined i-VTEC with VTC, which added variable timing control, allowing the automaker to further fine-tune power and efficiency. On V6 engines, i-VTEC with VCM enabled cylinder deactivation for improved fuel efficiency when full power was not needed. VTEC Turbo, meanwhile, combines VTEC and VTC with turbocharger-optimized cam timing for turbocharged engines.
