Civic IMA
Published: 15th November 2002
The aim of regenerative braking is to reclaim as much energy as possible during deceleration, and the engine therefore needs to provide as little resistance as possible. In a traditional engine, the pumping action of the cylinders will actually provide a moderate amount of resistance, or ‘engine braking’. The Civic IMA therefore features a cylinder idling system which effectively reduces engine drag by closing the intake and exhaust valves on up to three of the four cylinders enabling the pistons to move more freely within the cylinders, thus allowing the generator to provide maximum resistance (instead of the engine) and, consequently, to produce more electricity.
The system uses Honda's VTEC (Variable Valve Timing and Lift Electronic Control) technology to close the intake and exhaust valves on up to 3 of the 4 cylinders at engine speeds as low as 1000 rpm.
Nitrogen Oxides-Absorptive Catalytic Converter
Lean air-fuel ratios improve fuel economy and reduce hydrocarbons (HC), carbon monoxide (CO) and oxides of nitrogen (NOx). However, conventional 3-way catalysts are not very effective at converting NOx into normal nitrogen when excess oxygen is present. To keep NOx emissions within ULEV levels, Honda engineers developed a NOx-absorptive catalytic converter. The catalyst uses a proprietary mixture of platinum and other metals to attract NOx molecules to its surface during lean air-fuel mixture combustion. Then, when the IMA engine is operating with a richer air-fuel ratio, the catalyst combines these with the hydrocarbons and CO present in the exhaust to form water vapour, carbon dioxide and nitrogen. The Civic Hybrid will meet the forthcoming Euro 4 emission standard.
Automatic Idle Stop
The petrol engine is automatically turned off during complete stops under most circumstances and uses the electric motor to re-start the engine. The Idle Stop feature is not activated during the first few minutes of engine startup or if the automatic climate control system is being used in air conditioning mode and "Economy Mode" is not selected.
Electronic Instrument Display
Since the Civic IMA uses a unique powertrain, the vehicle's gauges and readouts are unique, too. The digital and analogue electronic instrument display features the traditional set of meters along with comprehensive IMA readouts. When the ignition is turned off, the panels appear blank (black). When the ignition is turned on, the numbers are backlit with high-tech blue and red needles against a black background. A dimmer switch is located just to the right of the odometer and the gauges automatically adjust to night-time mode when the lights are turned on.
The electronic instrument display allows the driver to monitor more than 23 vehicle systems with the following instrument readouts:
- Speedometer (analogue) with large numbers
- Tachometer (analogue) with large numbers
- Shift Light: Indicates the correct time to shift for maximum economy
- Auto Stop: When the engine turns off automatically using the Idle Stop feature, this light turns on
- Miscellaneous Indicator Lights: Oil pressure, low fuel, SRS, EPS, IMA, parking brake and battery
- Odometer with Dual Trip Meters (digital): Displays vehicle mileage and has two trip meters, marked A and B. Mileage display controlled by pushing the Select/Reset button located under the speedometer
- Fuel Economy Estimator - (digital): Shows numerical estimate of miles per gallon for either trip A or trip B mileage Instantaneous Fuel Economy Meter: Bar graph meter (with numbers)
- shows an estimate of real time fuel economy
- IMA Charge/Assist Meters (LCD): Indicates when the IMA battery is being charged or when it is providing electrical power assist
- IMA Battery Charge Level (LCD): Indicates how much power the battery has stored
- Fuel Gauge (LCD)
- Engine Temperature (LCD)
