First Drive: Honda Accord Plug-In Hybrid Mule

Honda’s reputation as an innovator and technology leader wasn’t earned with the first hybrid brought to the U.S. market or its stubborn commitment to a hydrogen-powered prototype. 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.

The company that once sold an affordable compact so clean it met emissions standards without a catalytic converter is hell bent on owning the hybrid market -- small as it may be, Prius be damned, and cost no object. So next year, Honda will add to its crowded stable of hybrids -- CR-Z, Civic, and Insight -- with a mid-size plug-in hybrid.

Not your typical Honda hybridHonda’s plug-in hybrid powertrain is far more sophisticated than the simple Integrated Motor Assist system found in Honda’s existing hybrids. It is also significantly different than the configurations used by the Toyota Prius and the Chevrolet Volt. 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.

A test drive shorter than its electric rangeOver an extremely short, city-like loop, we sampled the hybrid powertrain packaged in the chassis of the current Honda Accord. The electric motor is plenty powerful to move at a normal pace without calling on the gas engine. Stomp on the throttle, though, and there’s a slight lag in power delivery and a CVT-like audible awakening as the engine spins up to high rpm and parks itself there. The Honda mule drove with less moaning than a Prius but less engine isolation than the Volt. Maximum acceleration is adequate but not quick.

We were never able to discern if the engine was driving the front wheels, although that doesn’t necessarily mean the system is seamless. It’s possible that the computer simply never saw fit to engage the clutch during our limited test drive. Brakes are easily modulated by hybrid standards.

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. If Honda delivers on its claimed electric range of 10 to 15 miles, the mid-size plug-in hybrid will be aimed squarely at Toyota’s forthcoming Prius plug-in, a car that will certainly benefit from instant recognition as a hybrid.

The mysteries that remainIt’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.

Source;
http://www.automobilemag.com/reviews/driven/1112_honda_plug_in_hybrid_mule_first_drive/index.html