The mysteries that remain
It’s clear that Honda is hoping the more sophisticated powertrain will be a feather in its cap and a step toward reclaiming its reputation as a technology leader. For that to happen, though, buyers will have to respond to this hybrid more strongly than they have to any of Honda’s previous gas/electric cars. While the plug-in hybrid features some genuine innovations, its chance of success depends just as much on unknowns like styling, pricing, and fuel economy.

"[...] Honda built its brand on the fundamentals of its most accessible and popular vehicles. Americans admired the simplest solutions to the most complex problems; they respected diligent engineering that set a standard of continuous improvement; and they believed in the company that was consistently one step ahead of the competition. [...]

Honda’s plug-in hybrid powertrain is far more sophisticated than the simple Integrated Motor Assist system found in Honda’s existing hybrids. [...] No matter whether the Honda plug-in is relying on energy from its 6-kWh lithium-ion battery or its fuel tank, the wheels are primarily powered by a 161-hp electric motor. A second electric motor functions as a generator to convert power from a 2.0-liter four-cylinder into electricity for range far beyond the battery’s 10 to 15 miles. If the driver calls for quick acceleration or exceeds 62 mph, the gas engine will also kick on before the battery’s charge is exhausted. Recharging takes about one and a half hours with a 240-volt connection.

The Honda’s unusual trick (all good hybrids have at least one) is that the gas engine can be mated to the front wheels through a fixed gear ratio. While single-speed transmissions are common in electric vehicles, gas engines require multi-speed gearboxes to match the narrow rpm band where the engine is most efficient with the wide range of road speeds. Both the Prius and the Volt use continuously variable transmissions to blend electric and gas power on its way to the wheels. Honda’s single gear ratio has been optimized for low-load highway cruising, such that the gas engine never engages the wheels below 40 mph. An electronically controlled clutch engages the engine when the computer decides to send power directly from the gas engine to the wheels. [...]

Honda has committed to production for 2012, but it hasn’t let on if the powertrain will appear in the next Accord or an exclusive hybrid model. [...] "