3-stage VTEC
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An implementation of VTEC-E and standard VTEC, the 3-stage VTEC is present in the D15B engine and the seventh generation SOHC Civic of the Philippines. The engine is notable for its excellent economy along with good power output.
The technology is named so because of its 3 'stages' of VTEC implementation, explained below.
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[edit] Stage 1 - VTEC-E
An implementation of VTEC for economy, it turns off one intake valve per cylinder in the 16-valve engine, and attains lean burn mode. The lean burn mode gets the air to fuel ratio above the 14.7:1 stoichiometric ratio and thus enables extra fuel saving. This can lead to km/l averages of 30 if driven at a constant speed of 60 km/h.
The VTEC-E mode engages in the D15B from 0–2500 RPM.
[edit] Stage 2
From 2500–6000 RPM, the VTEC-E mode turns off and all of the engine's intake valves are used. The engine is now like any other normal VTEC engine when the VTEC isn't 'on'.
[edit] Stage 3 - VTEC
From 6000 RPM (up to rev limit) the engine's VTEC wild cam is engaged, increasing performance and giving 130 hp at 7000 RPM in the D15B
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Http://asia.vtec.net/spfeature/vtecimpl/img9.jpg
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