Honda Introduces Variable Cylinder Management V-6
June 18, 2003
Honda Motor Co. today introduced a new V-6 engine featuring the latest iteration of its i-VTEC ('intelligent' VTEC) technology. Through new 'Variable Cylinder Management' technology, the V-6 3.0-liter i-VTEC engine runs on all six cylinders during acceleration and when high output is required, yet employs only three cylinders during cruising and at low engine loads. The new engine thus combines the effortless performance of a 3.0-liter V-6 engine, while offering superior fuel economy comparable to that of a 2.4-liter four-cylinder engine. This new powertrain will debut in the new Inspire sedan scheduled for release in Japan this month.
In addition to its low fuel consumption, this V-6 3.0-liter i-VTEC engine also significantly reduces exhaust emissions, helping the Inspire meet Japan's Ministry of Land, Infrastructure, and Transportation requirements for Ultra-Low Emissions and 2010 fuel consumption standards, making it eligible for preferential 'Green Tax' treatment. The new engine achieves this by combining high-density catalytic converters located directly below each cylinder head for further improved exhaust gas processing at low engine temperatures with exceptionally fine air/fuel ratio control.
'Variable Cylinder Management' system analyses throttle opening, vehicle speed, engine speed, and gearing to determine that the car is cruising, and then idles the intake and exhaust valves of the three cylinders in the rear cylinder bank. With zero valve lift, the cylinders are sealed, and no fuel is injected. Pumping losses are thus reduced by as much as 65% and low fuel consumption is realised.
When operating in 3-cylinder mode, engine vibration is reduced by extrapolating vibration from the change in crankshaft rotation speed and sending the information to the 'active control' engine mount, which compresses/extends an actuator in same-phase, same-period motion to dampen the engine mount. Similarly, a speaker creates an opposite phase sound or 'active noise control', to provide a cancelling effect, for a quieter interior which leaves the driver unaware of changes in cylinder activation.