Considering Clarity

The Honda Clarity Plug-In Hybrid is the third of the Clarity models to be launched. Not only is it a highly competitive hybrid in its own right, but it also is part of a clever strategy being deployed by Honda to achieve economies of scale in electrified vehicles.

The Honda Clarity is one of the greatest examples of what may become a new approach to the development of automobiles.

That is, for a number of years OEMs have been practicing a platform strategy whereby there is a basic underlying architecture engineered, then there is a “top hat” fitted on top of it. This allows there to be variations of product with minimized development costs.

One of the most notable examples of this was executed by the then-Chrysler Corp. in the early 1990s. It created the LH platform from which it derived cars as different as the stately, stylish Chrysler 300 sedan to the Dodge Magnum station wagon. Today it is running the LX platform, which underpins the 300 as well as the Dodge Challenger, a two-door muscle car.

In these and in many other instances, the fundamental nature of the car is, in effect, disguised and modified so that the customer is likely to have no idea of the similarities between the widely disparate vehicles. 

But there are savings accrued in the context of engineering development costs.

Of course, there are other takes on this that are somewhat more straight-forward. Consider the Chevrolet Colorado and the GMC Canyon pickups. They are essentially the same vehicle with comparatively small amounts of differences between the two. There are changes to the fascias and the lamps, to the interior amenities. There is “enough” differentiation to make it worthwhile for someone to select one rather than the other.

The approach that Honda is taking with the Clarity—and it must be noted that another company that is doing much the same thing is Hyundai with the Ioniq—is to make one car and to put in three completely different powertrains. There is the hydrogen fuel-cell clarity. A full battery electric Clarity. And now a plug-in hybrid Clarity.

Realize this is not the same thing as having a car available with a four- or six-cylinder car, turbocharged or normally aspirated. This is not even the same thing as having a traditional internally combustion engine powered vehicle that is then built in a hybrid version.

These are three entirely different kinds of powertrains.

And yet these vehicles are essentially otherwise exactly the same.

Let’s face it: the volumes for alternative powertrain vehicles are modest at most. Honda is predicting that over the next four years there will be a total of just 75,000 Claritys sold in the U.S. (with, according to Steve Center, vice president, Connected and Environmental Business Development, American Honda, “the vast majority being the plug-in,” although he thinks that in the long term the fuel cell vehicle, as it provides a 366-mile range and a hydrogen refueling time of five minutes or less, “has the greatest potential.”). So the Clarity—which has a purpose-engineered platform—and comparatively economical price points (the starting prices, as in MSRP and destination charges, for the three vehicles are $59,380 for the Clarity Fuel Cell; $37,510 for the Electric; and $34,290 for the Plug-In Hybrid)—is something that Honda is undoubtedly going to have a bit of a struggle achieving payback for (although it should be noted that the U.S. isn’t the only market for the car, so the 75,000 number isn’t the total), but a far less daunting challenge given the fact that it is using the same underpinnings, skin and interior across the board.

So unlike the cases with Challenger et. al and the Colorado/Canyon, there is no disguising.

The visible and tactile aspects of the Claritys are essentially identical, yet the characters of the cars are different because of what’s under the hood.

Kiyoshi Shimizu, development leader, Clarity Series, Honda R&D, says that the foundational work on the Clarity took five years at the company’s R&D facility in Torrance, California. “The team and I wanted to create a vehicle that would meet every need of the customer without compromise.”

So they developed not only the overall vehicle, but the powertrains, as well. “We don’t think that any single one of these technologies will solve all of the issues regarding CO2 reduction. Fuel-cell, battery electric and plug-in hybrid—we need them all,” Shimizu says.

The Plug-In
The Clarity Plug-In uses a two-motor hybrid setup. It is mainly propelled by its Honda-designed, 181-hp AC synchronous traction motor. The second motor is an integrated starter/generator motor that is attached to the 103-hp 1.5-liter Atkinson cycle engine that has a 40 percent thermal efficiency. This second motor generates electricity that goes directly to the traction motor or sends it to the 17-kWh lithium-ion battery pack. The pack consists of 168 cells that are organized into 14 modules; the intelligent power unit is water-cooled to facilitate battery performance, particularly in high-load and high-temperature conditions. The battery pack is located beneath the passenger compartment so as to maximize passenger and cargo space. The location also lowers the center of gravity for the vehicle, which improves handling. There is also an electric servo brake system that is used for regenerative braking.

The vehicle has 47 miles of full electric range. With a Level 2, 240-volt charger, it can be 100 percent recharged in 2.5 hours. That full electric operation is one of the three modes the Clarity operates in.

Then there are hybrid and engine drive modes. In the first-named, the vehicle operates as a series hybrid: the traction motor, which is coupled to the engine and the generator motor, propels the vehicle.

Since the gasoline engine can be decoupled from the rest of the hybrid powertrain, it only operates as needed. Depending on the battery’s state of charge and other parameters, the engine will automatically shut off during deceleration, or when the vehicle is at a stop. When needed, the gasoline engine restarts automatically, without action from the driver.

Then there is the engine mode, where the operation is that of a parallel hybrid: there is a lock-up clutch that attaches the gas engine to the traction motor to power the front wheels. Here is where peak system output is achieved: 212 hp. The vehicle operates in this mode in instances like driving at medium to high speeds.

Two notable points. One is that there isn’t a conventional transmission but a fixed, single-speed setup. The other is that all of this is seamlessly controlled by a power-control unit.

The Clarity Plug-In has an electric-only, miles-per-gallon of gasoline equivalence of 110 miles. The miles per gallon attained by using the engine (both as a generator and as, well, an engine that drives the front wheels) is 44 mpg city, 40 mpg highway, 
42 mpg combined).

Honda has a global goal of having two-thirds of its vehicles electrified by 2030. The Clarity approach—fuel cell, battery electric and now plug-in hybrid—is one that will help reach that figure.