Honda Insight

Honda Insight

Manufacturer	Honda
Production	1999–2006
Assembly	Suzuka, Mie, Japan
Class	Subcompact
Body style(s)	2-door hatchback
Layout	Front-engine, front-wheel drive
Engine(s)	Gasoline: 0.995 L lean-burn I3 12-valve SOHC Electric: 144 volt 10 kW
Transmission(s)	5-speed manual Continuously variable transmission
Wheelbase	2400 mm (94.5 in)
Length	3945 mm (155.3 in)
Width	1695 mm (66.7 in)
Height	1355 mm (53.3 in)
Curb weight	Manual w/o AC 838 kg (1847 lb) Manual w/ AC 852 kg (1878 lb) CVT w/ AC 891 kg (1964 lb)

The Honda Insight is a two-seater hybrid automobile manufactured by the Japanese automaker Honda.

The Insight was the first mass-produced hybrid automobile sold in the United States, introduced in 1999.At its height, it achieved nearly 70 miles per gallon (3.4 L per 100 km). (In Japan, the first generation of the Toyota Prius was launched in 1997.) According to the EPA, the 5-speed manual transmission variant of the Insight was the most fuel-efficient mass-produced automobile sold in the United States. The Insight also features low emissions: the California Air Resources Board gave the 5-speed model a ULEV rating, and the CVT model earned a SULEV rating. (The 5-speed's lean-burn ability is a trade-off which increases efficiency at the expense of slightly higher NOx emissions.)

History

Upon its introduction to the United States in December 1999 (as a year "2000" model car), the Honda Insight was the first mass-produced hybrid automobile sold in the country. The first generation of the Toyota Prius, however, had gone on sale in Japan in 1997. Hybrid technology, which combined two different power sources -- in the Insight's case, a regular internal combustion engine and an electric motor powered by Nickel-Metal Hydride cells -- was unproven on the American market, and at the time of release was not considered viable. Previous efforts to make environmentally-friendly cars had focused on electric cars. The primary argument against hybrids was that the cost and weight of having two different motors would make the vehicles impractical.

The Insight, however, was introduced at a price of just under US $20,000. Other hybrids soon followed, with the Toyota Prius arriving in June of 2000. Honda rolled out a hybrid version of the Honda Civic in 2002, followed by Toyota's relaunch of the Prius in 2003. In the fall of 2004 Ford became the first American automotive manufacturer to bring a hybrid to market with the Ford Escape hybrid.

The car remained the highest mileage machine while it was produced and is still the leader of any current car. The Insight earned an EPA mileage estimate of 70 miles per gallon in highway driving, 61 mpg city. With air conditioning it was 66/60. With a CVT it was 57/56. Some drivers wind up with worse mileage; others routinely report real world mileage close to, and often exceeding, the EPA numbers. Insight aficionados, the more extreme of whom are called "hypermilers", compete to eke out as many miles as possible from a tank.

Upon the Insight's release, Honda challenged several automotive magazines to a competition to see who could obtain the best mileage on the 195-mile (314 km) drive from Columbus, Ohio to Detroit. The contest was won by Car and Driver magazine, which rigged a box behind an SUV, and had the Insight drive within the confines of the box. Without any wind resistance, the Insight made the trip with mileage of 121.7 miles per gallon, while averaging 58 miles per hour. A two-year test of an Insight with air conditioning, driven 40,000 miles (64,000 km), averaged 48 miles per gallon. Total global sales for the Insight amounted to only around 18,000. When the Insight debuted, gas cost only $1.39 a gallon.

Under the Energy Policy Act of 2005 in the United States, the Honda Insight was eligible for a $1,450 tax credit.

The gasoline engine is a nominal 70 hp, 1-liter, 3-cylinder unit. The electrical motor assist adds in another 10 kW (approx 12 hp) when called on, and similarly provides significant deceleration when used in regenerative mode for braking. (This both improves mileage and also dramatically extends the lifetime for the brake shoes).

The Insight addressed many problems of electric vehicles, such as their extremely limited range. When the car is not driving the engine shuts off. The digital displays on the dashboard display mileage instantaneously. On the manual transmission up and down arrows suggest when to shift gears. In California, the state with the most-stringent fuel economy standards, the manual-transmission Insight was rated as an ultra-low-emission vehicle and the CVT transmission was rated Super-ultra-low-emission vehicle.

Until 2003 Honda and Toyota sold roughly similar numbers of hybrids, but in 2004 the Prius sales doubled. Sales of hybrids in Europe were even lower than in America because of the popularity and infrastructure to support diesel cars in Europe. The Economist wrote: "The beauty of hybrids is that they do not require changes in driver behaviour or fuel infrastructure."

In 2006, Honda decided to cancel production on the Insight because of dwindling sales and rising sales of the Honda Civic Hybrid. Hybrid insiders also noted the fact that the Insight was only a 2-seater made the Toyota Prius the preferred choice for those desiring to drive green.

Design

The Honda Insight was a subcompact hatchback 3945 mm (155.1 in) in length with a wheelbase of 2400 mm (94.5 in) a height of 1355 mm (53.3 in) and a width of 1695 mm (66.7 in). The Insight was only available as a two-seater. Only three different trims were available: a manual transmission without air-conditioning, a manual transmission with air-conditioning, and a continuously variable transmission with air-conditioning. Although produced until 2006, the only major change was the introduction of a trunk mounted, front controlled, multiple CD changer.

One key in increasing the vehicle's fuel efficiency was reducing the mass via the extensive use of aluminium and plastic. Honda built the insight with aluminum front brake calipers and rear brake drums; the fuel tank was plastic; the engine mounts are aluminum; and the exhaust was a small, thin wall pipe.The entire weight of the Insight was only 1847 lb (838 kg) for a manual transmission or 1964 lb (891 kg) for the CVT with air conditioning.

The flat back of the Insight was similar to the CRX, while the broad, rounded hood resembled the design of the Honda Civic. The shape of the Insight was considered too unusual by some drivers, much like GM's EV1. The New York Times wrote that the Honda Insight and the EV1 "suggested Popeye's pal, Olive Oyl, in her ankle-length dress. The rear fender skirts seemed frumpy."

Technology

Honda Insight IMA

The Insight uses the first generation of Honda's Integrated Motor Assist ( IMA) hybrid technology. (The next generation, used in the Honda Civic Hybrid, is much more space-efficient.) The Insight has a 3-cylinder 1.0 Liter engine and a brushless 10-kWelectric motor located on the crankshaft.Buried behind the driver's and the passenger's seats are a set of commercial grade "D" sized NiMH batteries wired up to provide a nominal 144 V DC.During heavy acceleration, the electric motor provides additional power; during deceleration, the motor acts as a generator and recharges the batteries using a process called regenerative braking. A computer control module regulates how much power comes from the internal combustion engine, and how much from the electric motor; in the CVT variant, it also finds the optimal gear ratio. The current battery charge is shown on the dashboard, as is the instantaneous fuel efficiency and current state of the electric motor — whether it is assisting the engine or charging the batteries.

Additional mileage enhancements are courtesy of high pressure, low rolling resistance tires and the use of extremely slippery "0w-20" synthetic oil.

Unlike the Toyota Prius, which has a planetary gearset, the original Insight had a conventional manual transmission. Starting with the 2001 model, a CVT variant of the Insight was available; the CVT is similar to that used in the Honda Civic Hybrid and the Honda Logo. The Insight is not considered a "full" hybrid vehicle because it cannot run on the electric motor alone, whereas its competitor, the Prius, can be operated solely on the electric motor. A feature shared by the two hybrids (and now appearing in others) is the ability to automatically turn off the engine when the vehicle is at a stop (and restart it upon movement). Since it is more powerful (10 kW) than most starters of conventional cars, the Insight's electric motor can start the engine nearly instantaneously.

The Integrated Motor Assist is run by an "Intelligent Power Unit (IPU)", a desktop computer-sized box. The Intelligent Power Unit, the Power control Unit, the Electronic Control Unit, the vehicle's batteries, converter and a high-voltage inverter are all located under the cargo floor of the vehicle, behind the seats. Also to maximize mileage, the Insight was very aerodynamic. The Insight had one of the lowest coefficients of drag of any car on the market, although its 0.25 coefficient was not as low as the EV1's 0.19.

The Insight was available with a manual transmission or a continuously variable transmission (CVT). A traditional transmission shifts between a fixed set of engine-to-wheel ratios; however, a CVT allows for an infinite set of ratios between its lowest gear and its highest. The CVT transmission was classified as a super-low emissions vehicle.

Manufacturing

The Insight was assembled at the Honda factory in Suzuka, Japan, where the Honda NSX and the Honda S2000 are also assembled. The Insight and the NSX are aluminum bodies, while the S2000 employs a steel body. Sales were small, but Honda sees the vehicle as more of a halo car than a volume seller.

At the 2003 Tokyo Motor Show, Honda introduced the concept car Honda IMAS, an extremely fuel-efficient and lightweight hybrid car made of aluminum and carbon fiber, which was perceived by most observers to be the future direction where the Insight is heading.

In May 2006, Honda announced that production of the Insight would stop in September 2006. According to Honda, it will be replaced by a new hybrid car smaller than the eighth generation Civic. While year round production of the Insight would stop in 2006, limited production during the winter would continue as necessary, presumably for parts. It was designed as a real world test car for hybrid technology and to gauge driving habits.

Common Issues affecting efficiency & Performance

The Insight employs 2 electrical ground connections to the chassis, both visible on the driver's side of the engine bay. These ground connections are made of rigid copper wire and are prone to fatigue failure. Corroded or broken ground connections can cause multiple types of IMA-related failures, or even lackluster performance of the hybrid system. The Insight was also sold with Bridgestone RE92 low rolling resistance tires in the 165/65-14 tire size. Deviating to heavier, wider, higher traction tires creates more drag on the engine and reduces the fuel economy considerably by preventing entrance into "Lean Burn" mode at highway speeds. The stock RE92 tires were specified at 40PSI front and 38PSI rear, which is much higher than typical settings for comparable vehicles. Deviation from intended tire pressures also has a large effect on the fuel economy of the Insight. When replacing spark plugs, each of the 3 cylinders is stamped with a unique letter (A, B, C or D) denoting the threading index of the particular cylinder. Spark plugs should be purchased and installed accordingly to match the indexing of each cylinder correctly.

Replacement battery pack cost

Since the Insight's introduction, many have wondered what costs an Insight owner would face if the car's NiMH battery pack needs replacing. As of October 2006, Honda is paying the replacement cost of these batteries on cars with up to 150,000 miles (240,000 km) of use.As of September 2007, one dealer quote is US$5000. Garage mechanics have recently started attempting replacing Insight batteries with either Prius sub-packs or Civic Hybrid subpacks. As of the date of this edit (Mar 2008) the Civic Hybrid subpacks appear to be a direct replacement at an affordable $300 per used battery pack due to larger production volumes.

Awards

The Insight's engine won the International Engine of the Year award for 2000, and continued to hold the "Sub-1 liter" size category for the next six years. The Insight was nominated for the North American Car of the Year award for 2001.

Customizations

A number of Insight owners have performed some interesting and unique customization to their cars over the years.

Honda hybrids like the Insight are Parallel Hybrids which at first glance would not seem to benefit much from a plug-in hybrid conversion as they do not have an EV-mode like the Toyota Prius. However by using a larger battery the 10 kW (13 hp) IMA could be run in a constant assist mode to displace gas consumption and push the mileage well into the one-hundreds on the freeway. The Insight is a very light and aerodynamic vehicle which makes it rather attractive for conversion.

Manual IMA

The MIMA or (Manual IMA (Integrated Motor Assist)) project has developed a component and pre-assembled kit to allow Honda Insight drivers to manually control both IMA Assist and Regen. This modification enables the driver to alter the IMA's normal assist and regen characteristics. It also makes it possible to directly input assist and regen with an analog joystick. It is currently only available for the Insight but not the Civic or Accord. While not an Insight PHEV (Plug-in hybrid) project itself, it makes it possible to use additional battery capacity in a blended mode similar to Prius PHEV at speeds greater than 34 mph (55 km/h).

MIMA allows the driver to set an aggressive assist type profile allowing the IMA to contribute up to 10 kW (13 hp) of continuous power. This would rapidly deplete the stock battery which may reach empty within 5 minutes or 5 miles (8.0 km). Some Insight drivers may already be familiar with Recalibration Events, Recals, which are essentially the manifestation or the State Of Charge Drift portion of the vehicles battery management routines. While the most common Recals are negative and occur when the SOC reaches a lower limit, it is also possible to recalibrate or drift up if the SOC is determined to be higher than expected. Such behavior makes possible State Of Charge Manipulation by simply keeping the battery's voltage or perceived voltage near the upper limit.

Technically, as long as the lower SOC limit is not reached, MIMA makes it possible to command any desired level of IMA assistance which diminishes the importance of SOC Manipulation. Both simple and hybrid Battery Pack Configurations would be equally effective in such a conversion because of the previous point. A hybrid pack would leave the stock battery in place and might eliminate the need for a Battery Tap Emulator, yet a simple configuration replacing the NiMH pack with a superior Lithium battery would maximize energy density and keep vehicle weight well under 2000 pounds. A battery charger would be required and might also double as a hybrid pack's power regulation device which could lessen the constraints on choosing a battery packs geometry (voltage, cells, or number of batteries).

It should however be noted that Li-Ion battery packs have been known to have catastrophic malfunctions. Its very common for model aircraft users who use Li-Ion batteries to experience fires or even outright explosions hours or even days after a model has crashed,even when the battery pack appears to be undamaged. This highlights the possibility that not only might a Li_Ion battery pack catch fire or possibly explode immediately,but might also appear perfectly normal until a much later time. It may also be possible that a single cell exploding in a densely packed battery pack might act as a detonator setting off other cells in the pack. Clearly the idea of 5000 cell phone batteries,packed into the size or a large suitcase simultaneously detonating in a bad accident should make any potential home-brew modifications using Li-Ion technology inadvisable unless these issues can be accounted for and mitigated.

Easy Modifications

The clutch pedal switch may be shorted in parallel to disable the IMA charge/discharge function. Disabling the IMA system while climbing steep hills may be beneficial for overall MPG.

The brake pedal switch may be shorted in parallel to enable full electric regenerative braking without using the brake pedal.