If there's one discipline where Honda excels, it's in the design and engineering of small cars. The 2010 Insight melds componentry and concepts from two of the best small cars in the business: the 2009 Fit and Civic. The Fit serves as the donor for much of the Insight's chassis design, while the Insight's powertrain is essentially a cost-reduced version of the Civic Hybrid's 1.3L Integrated Motor Assist powertrain.
Honda says the Insight's engine room has been lifted mostly intact from the 2009 Fit, but the Insight's carefully aero-trimmed floorpan is a newly designed structure, facilitating optimal placement of the IMA system's Intelligent Power Unit (IPU). The IPU contains the battery modules and the Power Control Unit (PCU). In the Civic Hybrid, the IPU is wedged between the rear seatback and the trunk, but thanks to the Insight's space-saving torsion beam rear suspension design (borrowed from the Fit) and the size reduction of the IPU, Honda was able to position it beneath the floor in the rear of the vehicle. This design allows for a class-leading 15.9 cubic feet of cargo volume.
Less is More
On paper, the 2010 Insight's powertrain appears nearly identical to the Civic Hybrid's powertrain. Looking closer, there are some critical differences which result in reduced complexity as well as reduced manufacturing costs. The Civic Hybrid's 1.3L 8-valve dual spark configuration is retained, though the Insight utilizes a simplified 2-stage VTEC valvetrain compared to the Civic Hybrid's 3-stage VTEC system. This results in slightly less peak horsepower (88hp@5800 rpm) and torque (88lb-ft@4500 rpm) than the Civic's 1.3 develops (93hp@6000 rpm, 89lb-ft@4500 rpm). While output has dipped slightly, Honda's engineers have managed to make the Insight's engine 2% more fuel efficient. Additionally, the Civic Hybrid's 15kW (20hp) IMA motor (which doubles as the flywheel and generator in the IMA system) has been downsized to a 10kW (13hp) unit for duty in the Insight. This 33% reduction in output directly translates to a reduction in the demands placed upon the system's battery pack. Total system output for the 2010 Insight is 98hp @ 5800 rpm and 123lb-ft @ 1000-1500 rpm, compared to 110hp @ 6000 rpm and 123 lb-ft @ 1000-2500 rpm.
The battery portion of the new Insight's IPU is comprised of seven modules. Each module holds 12 individual D-cell sized 1.2V NiMH cells, for a total of 84 cells (100.8 volts). By comparison, the Civic Hybrid's battery pack is composed of 11 modules, for a system total of 158.4 volts. The net result is that the Insight's IPU is 19% smaller (now 48 Liters) and at 38kg, it is 28% lighter than the Civic's IPU. Battery technology advances such as thinner separators, increased electrode plate area, and an improvement in cathode corrosion resistance are credited with increasing the output capacity of each module by 30% while simultaneously improving durability by 30%. Interestingly, these are essentially the same improvements that Sanyo (Honda's supplier of batteries for the 2010 Insight) claims in the white papers for their "Eneloop" consumer battery technology. Coincidence? Perhaps, but Honda won't comment.
Just like the current Civic Hybrid, the Insight is capable of shutting down the gas engine and being powered solely by the electric motor in limited circumstances*. Many people, (including leading journalists and even current Civic Hybrid owners) were unaware that the current Civic Hybrid also possesses this capability. Given the parallel configuration of the Civic's IMA powertrain, this is understandable, since during times of electric-only operation, the driveshaft continues to turn even when the valves are sealed and fuel delivery is cut to the gasoline engine. This means that the tachometer still indicates that the engine is "running". With the Civic Hybrid, the only way to know for sure that the gasoline engine was disabled was to closely monitor the realtime fuel economy meter and the charge/assist indicator. If the fuel economy meter registered a maxed out condition (100mpg) while the charge/assist indicator simultaneously registered that there was an assist condition, then you could be pretty certain that the Civic hybrid was operating in electric-only mode. With the new Multi-information display in the 2010 Insight (on all models), now you can select the appropriate info screen and know with absolute certainty any time the Insight is operating in electric-only mode.
What do you mean by "limited circumstances*"?
Lots of people look at gasoline-hybrids and see the benefits of combining the two methods of propulsion and automatically think "Why not power the car on electricty MORE often for even greater fuel economy?". There's not really a simple answer to that question except to say that at a certain point you reach a prohibitive level of cost, complexity, and/or weight. The IMA motor in the Insight is rather small at a rated output of 13hp (10 kW), so that will naturally limit the ability of the system to propel the Insight solely on electricity. Even more importantly, if you run through a few quick calculations you'll discover that in order for the electric motor to develop its rated 13hp, each 1.2V D-sized cell in the 84-cell battery pack will be required to deliver roughly 100-amperes of current. While the Insight's battery technology permits such massive discharge currents, for the sake of battery longevity, periods of this magnitude of discharge are kept quite brief. Otherwise, the heat generated by a protracted discharge at this rate would rapidly degrade the batteries. Furthermore, if we were theoretically able to ignore the heat issues (which we can't), and if the batteries operated in a perfectly linear discharge fashion (which they don't), the battery pack would only deliver enough juice for a little over 3 minutes at full draw. If you consider what it would take to address these issues, it should quickly answer the above question.
Less Frost, Less Cost
In another cost-saving bid, the Civic hybrid's dual scroll air-conditioning compressor has been scrapped in favor of a more traditional compressor for the 2010 Insight. This means that during periods of idle-stop, the Insight's A/C compressor is idled, and thus the climate control system is unable to cool the air until the engine is fired again.
While most of the differences between the Insight and Honda Civic Hybrid's powertrain generally represent feature-deletes, there's one feature that the Insight can claim as an exclusive for any Honda in the US market, and that's the simulated 7-speed "sequential" sport transmission mode that is standard on EX models. This is essentially the same system that has been offered in Jazz and Fit models in other markets for several years, but it is a pretty nice differentiator for the US-market.
Dimensionally speaking, the Insight pretty much splits the difference between the Civic and Fit. Listed at 172.3 in., the 2010 Insight is 10.7 in. longer than the 2009 Fit, and 5.0 in. shorter than the 2009 Civic. At 100.4 inches, the Insight's wheelbase is 2 in. longer than the 2009 Fit's, but 5.9 in. short of the 2009 Civic's. Speaking in vertical terms, the 56.2 in. tall Insight is shorter than both the Fit (60.0 in.) and the Civic (56.5 in.). On the scales, the Insight once again comes in between the Fit and Civic as well; fully optioned out from the factory, it is listed at 2734 lb., which makes it about 120 lb. heavier than a Fit Sport Navi and 145 lb. lighter than a Civic Hybrid.
Eco Assist and Driver's Ed
One of the chief complaints amongst current hybrid owners involves observed fuel economy; in a nutshell, many owners are unable to achieve the efficiency numbers that are widely publicized for hybrid vehicles. Honda is very keen on satisfying their customers and keeping such complaints to a minimum, so they have developed a feature that serves dual roles. It is primarily advertised as a tool for optimizing fuel efficiency, but with its lifetime achievement scoring system, it also provides an electronic paper trail of historical data that reflects the driving habits of the owner. A hidden benefit for Honda is that this is something that can easily be examined in the case of owner complaints about fuel economy. Based upon our driving time with the Insight, this really shouldn't be much of an issue, however.
Honda's Eco Assist Guidance Function is the mechanism which provides instant feedback to the driver. This information is presented in several different ways, but the most user friendly fuel saving mechanism is incorporated within the Insight's high mounted digital speedometer.
The digital speedometer is designed such that the numerals appear almost holographic, floating in space in front of an arched band of color that acts as a sort of mood ring, glowing green when the driver is driving in an optimal manner, and switching to a cold blue when petrol is being swilled at a careless rate. If you find yourself somewhere in between the two extremes, you see a blend of the two colors, which is displayed as shades of teal. Most importantly, it's pretty easy to pay attention to the color of the band without shifting your focus away from the road.
Similar real time scoring information is also presented in a sort of bar graph format within one of many Eco Assist related pages on the MID (multi information display). During my time with the car, I didn't find this particular page of the MID to be a very useful display as it required a shift of focus that took my eyes well off the road. Instead, I preferred to set the MID to display the fuel consumption screen which shows the instant and average fuel economy, so I could occasionally glance down and monitor my progress.
Obeying the "mood ring" display is very effective for optimizing fuel economy while the information found in the MID is useful for fine tuning your results. Unfortunately, none of this trip computer information is available on the navi system's LCD screen. In my opinion, the Navi's $1800 pricetag would be much more palatable if Honda took better advantage of the LCD display's pixel count and fully integrated it with the Eco Assist Guide system.
As mentioned earlier, the Eco Assist system has a lifetime scoring component which keeps tabs on your driving patterns. If you consistently drive the car in an efficient manner, the system rewards you by unlocking a series of achievements. After you've acquired a number of feathers in your cap, you unlock one in a series of little trophies that are displayed on the MID. Unfortunately the system is not driver-centric, so for now there is no way to keep your spouse or friend from possibly damaging your achievement status when he or she drives your car.