Honda has introduced a new V6 engine featuring the latest iteration of its i-VTEC (‘intelligent’ VTEC) technology. Through new ‘Variable Cylinder Management’ technology, the V6 3.0-litre 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 is claimed to combine the effortless performance of a 3.0-litre V6 engine, while offering superior fuel economy of 11.6 km/litre – comparable to that of a 2.4-litre four-cylinder engine. This new powertrain will debut in the new Inspire model scheduled for release in Japan on Thursday 19 June.
In addition to its low fuel consumption, this V6 3.0-litre 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.
The adoption of a variable intake system, over-sized intake valves, and low back-pressure catalytic converters further improves engine respiration efficiency, helping deliver class-leading performance, with maximum output of 184 kW (250 PS) and maximum torque of 296 Nm (30.2 kg/m)*3, all on unleaded regular petrol.
The ‘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 three-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.