Engine & Transmission

For the European market, Opirus is powered by a 24-valve, 3.5-litre V6 petrol engine offering a compelling mix of power and performance. Designed using computer aided technology and manufactured utilising lightweight alloys such as aluminium for the cylinder block and power-cast metal for the connecting rods, the Opirus engine is very light and offers an excellent power-to-weight ratio.

The engine is fitted with a drive-by-wire electronic throttle, linked to the traction control system and electronic stability programme computers. Double overhead camshafts per cylinder bank operate 4-valves per cylinder - two intake and two exhaust valves - to ensure complete and efficient combustion of fuel. Good useable power is available from just 2,000 rpm, and the engine will rev to a maximum of 6,300 rpm before the electronic cut-off intervenes.

The engine´s peak power output of 149 kW (203ps) is achieved at 5,500rpm, while maximum torque of 298 Nm (30.4 kg.m) is generated at 3,500rpm. More than 90% of maximum torque is available across a broad rev-band, from 2,000 to 5,000, contributing to Opirus´ feeling of effortless performance. The engine will propel the Opirus from standstill to 100 kph in 9.2 seconds, from 60-to-100 kph in 5.1 seconds, and onwards to a top speed 220 kph.

The appearance of the transversely-mounted engine is enhanced by the addition of a full engine bay cover to complement the engine cover itself. Both covers also play a role in subduing mechanical noise for greater vehicle refinement.

Transmission

The Opirus engine is mated to a five-speed automatic gearbox which offers drivers the choice of fully automatic adaptive operation or a sequential manual mode with the sportier handling of a clutch-less manual transmission.

The driver can select manual mode at any time when the gear selector is in the Drive position by pushing the gear stick into the shorter slot of the "H" gate. Pushing the gear stick forward then shifts up a gear and pulling it back shifts down - one ratio at a time, sequentially. Sensors measure engine speed and acceleration and, when appropriate, will limit the drivers choice of gear ratio to avoid over-revving the engine.

In fully automatic mode, gears are changed according to a pre-programmed ´adaptive´ shift pattern which allows the gearbox to adapt its characteristics to match the current driving style. The gearbox has four settings - D (Drive), N (Neutral), R (Reverse) and P (Park).

Gear changes are controlled by a neural network that monitors a range of parameters including acceleration, deceleration, engine speed, oil temperature and road conditions. An artificial intelligence program then selects the optimum gear, preventing frequent gear changes during ascents to improve power efficiency and using engine-braking on descents for improved stability. The position of the gear lever is shown by an LED display on the dashboard with a second numerical display indicating the current gear.

Improving shifting performance still further is an independent clutch control system. Each clutch is directly controlled by a separate hydraulic control valve making the gear shift smoother and more responsive.

Top gear in the five-speed transmission is a high ratio designed to deliver whisper-quiet cruising and improved fuel economy. For each 1,000 rpm of engine speed Opirus travels at 50 kph, so travelling on a European motorway at a typical cruising speed of 130 kph means the engine is running at just 2,600 rpm.