A Continuously Variable Transmission (CVT) is standard equipment on all Civic Hybrids. The newly designed transmission provides a wider range between the maximum and minimum gear ratios to enhance acceleration and minimize engine rpm at high speeds. The transmission provides smooth and predictable transitions and helps keep the IMA system operating at its peak efficiency.
A hybrid dual scroll air conditioning compressor that is both engine and internal electric motor-driven helps minimize the air conditioner's impact on fuel economy and allows Honda Civic Hybrid's automatic climate control system to operate even when the engine is in idle stop mode.
A cooperative regenerative braking system has been added that intelligently directs braking power between the hydraulic brakes and the electric motor (which acts as a generator to provide significant resistance for braking). Less reliance on the traditional braking system and reduced engine pumping losses translate into greater electrical regeneration (170 percent more than the 2005 Civic Hybrid) and ultimately improved fuel economy. When braking, a brake pedal sensor sends a signal to the vehicle's IMA computer (IPU). The computer activates a servo unit in the brake system's master cylinder that smoothly proportions braking power between the traditional hydraulic brakes and the electric motor to maximize regeneration. Previous versions of Honda's IMA systems proportioned braking power at a pre-set rate below the maximum regeneration threshold and with no variable proportioning.
Honda Civic Sedan and Civic Coupe Powertrain: 1.8-Liter / 5MT / 5AT- 1.8-liter i-VTEC 4-cylinder engine
- 5-Speed Manual Transmission
- Electronically-Controlled 5-Speed Automatic Transmission
Honda Civic Sedan and Civic Coupe benefit from a new generation of Honda engine technology that provides performance similar to a 2.0-liter engine and fuel economy similar to a 1.5-liter engine. The all-new 1.8-liter i-VTEC 4-cylinder engine produces 140 horsepower @ 6300 rpm and 128 lb-ft. of torque at 4300 rpm with an estimated EPA city/highway fuel economy of 30/40 miles per gallon. The new engine offers significantly improved low rpm torque and top end power. A new 5-speed automatic transmission (available) extracts this extra power to its fullest potential. Additional new Civic technology includes a drive-by-wire throttle control and a dual-stage air intake.
Honda Civic's 1.8-liter i-VTEC engine minimizes pumping losses during cruising and low engine load situations, an important factor in creating more efficient engines. Pumping losses are reduced when the variable valve timing allows an intake valve to remain open for a brief time period as the piston begins its compression stroke. By keeping an intake valve open during part of the compression stroke, some of the volume of unburned air/fuel mixture in the cylinder moves back inside the intake manifold and lowers the volume being compressed, or "pumped."
During cruising or other stable, low-load driving conditions, the new engine utilizes a dedicated set of cams to close one of the intake valves and retard that valve's timing, exerting backpressure on the air-fuel mixture. This reduces the actual intake air volume. Meanwhile, the throttle is opened wider to provide optimum control over engine output. Opening the throttle valve wider, in other words, widening the path that the air flows through - reduces pumping losses to result in a significant improvement in engine efficiency.
The pumping loss reduction yields fuel economy similar to an engine with a displacement of a 1.5-liter engine. The ability to reduce pumping losses during low engine loads allows for more aggressive tuning of the engine during high loads such as when accelerating. During high load situations, the VTEC system provides high output valve timing for maximum power. Gone is the normal valve timing, replaced by two fundamentally greater extremes. A dual-stage air intake, a lightweight powertrain and optimized gearing further add to the performance character of the vehicle.
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