24 Oct 05
Honda's new Civic is as radical to look at as the old one was sensible.
4Car will be bringing you a full road test during November, but, on the eve of Tokyo Motor Show we travelled to Honda's Takasu test track in Hokkaido, Japan, to sample an intriguing derivative of the new range: the Civic Hybrid.
As you can see, the Hybrid is a saloon rather than a hatchback. There's no information yet on whether Honda will make a hatchback version, but for now the Hybrid's availability purely as a four-door mirrors what happened with the old range, hybrid version of which, the Civic IMA, was based on the extremely dull saloon.
The new car looks a lot more interesting, both outside - with its short nose and MPV-like quarter windows ahead of the front doors - and inside, where it features a version of the double-layer dashboard that's so striking in the hatchback. This saloon has different rear suspension from the hatch - a full double-wishbone arrangement instead of a cheaper, more space-efficient torsion beam - but nevertheless the way the Hybrid drives gives a hint of what to expect when the hatchback goes on sale.
It's significant that the name is now Hybrid rather than IMA, which stood for Integrated Motor Assist. This is partly because Honda now trusts people to know what a hybrid is; partly because the new car can run, Prius-like, on the electric motor alone, which wasn't possible before. But the way the Civic achieves this is very different from Toyota's approach even though Honda is now also using a CVT (continuously variable) transmission.
In Honda's system, the 1.3-litre, 95bhp engine and the 20bhp electric motor are always connected to each other because the motor forms part of the flywheel. That means the engine's crankshaft is always turning, even when the Hybrid is moving under electricity alone - a mode that can happen under light loads and speeds of up to 30mph.
This doesn't create an enormous amount of resistance, because in this mode all the inlet and exhaust valves are shut by means of hydraulic de-actuators, which take the valve rockers away from the camshaft. So there are no compressions and no pumping losses; the residual air in two of the cylinders is compressed while that in the other two expands, so it all evens out. The engine is also designed to run with minimum friction.
This valve deactivation is an extra stage, added to the two i-VTEC variable valve-timing and lift modes that already exist, one for best torque at low revs, the other for best power at high revs. Talking of torque, the electric motor might not have much power, but it manages 76lb ft of torque at the zero rpm at which an electric motor always pushes hardest.
