Civic Hybrid (Honda UK)
Powertrain
The Civic Hybrid has a new 1.4-litre i-DSI petrol engine that works with a new, highly-efficient electric motor system to deliver economical motoring with low emissions.
Engine
The i-DSI petrol engine uses three stage i-VTEC valve control to achieve a combination of responsive driving and fuel economy. The valves are controlled by three hydraulic pathways, which couple and uncouple five rocker arm assemblies.
The really clever bit happens during deceleration, when the engine’s cylinders have their feet up. During this idle time, combustion in all four cylinders is stopped and each pot is sealed shut. This means the engine is not working as hard to pump fuel or air, so it’s immediately more efficient.
Not only that, but while the car is slowing down, the Civic Hybrid’s electric motor recovers energy generated through braking and uses it to charge the on-board battery. And as the 2006 car is more efficient than ever, it records a 10 per cent improvement in recovery of braking energy compared to the current Civic IMA, where only three cylinders are shut during idle.
The technology used to shut the cylinders, VCM (which stands for Variable Cylinder Management), is also used to shut all four cylinders when only little torque is required – during low speed cruising for example. In this mode the Hybrid is powered by the electric motor only, with the pistons running idle.
In addition, virtually everything possible has been done to the engine to reduce friction, including the use of aluminium die-cast pistons (which feature low thermal expansion for less friction under high-temperature conditions), ion-plated piston rings, and plateau honing of the cylinder walls for a smoother surface.
The engine features Honda’s i-DSI (intelligent Dual and Sequential Ignition) system that uses two spark plugs per cylinder and allows for more complete combustion of the fuel by firing the two spark plugs either at the same time or sequentially, depending on the driving conditions.