Overview
Based on the same class-leading chassis and suspension design that underpins the Accord V-6 sedan, the Accord hybrid makes use of an Electric Power Steering (EPS) system - similar to that in an S2000 and Acura NSX - as opposed to the hydraulic-powered variable assist rack-and-pinion setup in its gasoline-powered Accord siblings. The EPS system allows the Accord Hybrid to provide power steering even when the vehicle is in idle stop mode.
Already recognized as one of the more nimble entrants in the mid-sized class, all Accords employ a 4-wheel double wishbone suspension. This entirely independent suspension allows the Accord consistent linear tracking under all conditions, while minimizing body roll during hard cornering. When combined with the EPS system, the Accord Hybrid is able to enhance steering response and minimize torque steer associated with the increased horsepower to provide a very balanced and stable ride.
Key chassis features
- Front double wishbone suspension
- Rear subframe-mounted, 5-link double wishbone suspension
- Electric Power Steering (EPS)
- 4-wheel disc brakes with 3-channel anti-lock braking system (ABS)
- Electronic Brake Distribution
- Advanced Traction Control System with integrated Creep Aid System
- 16" alloy wheels with 215/60 R16 tires
Front double wishbone suspension
The Accord's double-wishbone front suspension is designed to maintain a stable ride under all driving conditions, including hard acceleration, braking and cornering. With a large lower arm connected directly to the front subframe and a smaller upper arm positioned high, above the wheel and tire, this suspension is able to isolate wheel movement and minimize the effects of bumpy roads intruding into the passenger cabin.
Rear Five-link Suspension
Mounted entirely to the Accord's rear subframe, its rear five-link double wishbone suspension is meant to keep the vehicle flat during hard cornering and minimize the amount of roll steer associated with most independent rear suspensions. By providing precise camber and toe control, this double wishbone suspension helps to keep a flat tire contact patch between the Accord and the road. Each of the five tubular steel links is designed to keep the rear wheels upright through their full range of movement in all conditions, including cornering at higher speeds.
With a compact design, the Accord's rear suspension was also developed to minimize the space it takes up behind the rear wheels, and thus maximize the cargo area in the Accord Hybrid's trunk. With the Intelligent Power Unit (IPU) of the IMA system mounted behind the rear seats, Accord Hybrid continues to have over 10 cubic feet of cargo area (11.2), down only 2.8 cu.-ft from a traditional Accord V-6 Sedan.
Electric Power Steering (EPS)
To allow for power steering operation during idle stop mode and further reduce fuel consumption while enhancing steering accuracy, the Accord Hybrid employs a modified version of the Electric Power Steering (EPS) system used in the S2000. This electric steering rack eliminates the need for power from the gasoline engine to regulate hydraulic pressure as in a traditional rack-and-pinion setup. Instead, a high-output motor replaces the oil pump. In addition, the high-mount design allows for longer tie rods, which reduces the amount of unwanted steering feedback during bumpy drives.
4-wheel disc brakes
With large, 11.1" ventilated front discs in front and solid disc brakes in the rear wheels, the Accord Hybrid continues to have one of the most effective braking arrangements in the mid-sized sedan segment, delivering smooth, linear and stable braking performance across a broad range of conditions and braking loads. The braking system is further enhanced by a standard anti-lock braking system and electronic brake distribution.
ABS
The standard Anti-lock Braking System (ABS) from the Accord V-6 carries on in the Accord Hybrid. This arrangement incorporates wheel sensors at each wheel and three control channels to modulate braking pressure. With this type of system, the ABS control unit is able to monitor wheel speed at each wheel and adjust braking pressure to each of the front drive wheels or both rear wheels jointly. As such, wheel lockup is avoided in virtually all driving conditions, including situations where one side of the vehicle has significantly less traction than the other. This is critical in the Accord Hybrid's ability to maintain steering control during hard braking in normal and adverse road conditions.
Electronic Brake Distribution
The ABS system is further enhanced by Electronic Brake Distribution (EBD) which adjusts braking pressure front-to-rear, based on the weight distribution of passengers and/or cargo. Weight distribution is determined via the relative difference in rotational speed of the front and rear wheels. Greater braking pressure, and subsequently stopping power, is directed to the rear wheels when cargo loads in the rear are heavier. This contributes to a more controlled stop, and in conjunction with the front double wishbone suspension minimizes "brake dive" during hard braking.
Traction Control System
An advanced Traction Control System (TCS) has been added to the Accord Hybrid to help harness the increased horsepower. Similar to previous Honda TCS systems, the Accord Hybrid's system uses wheel sensors to monitor the rotational speed of each wheel.
When wheel-slippage is detected at any wheel (higher rotational speed), the TCS pulses the brakes until traction is regained and all four wheels are again traveling at the same speed. The Accord Hybrid's TCS system is most effective at low speeds when the vehicle is accelerating on a split-traction surface.
Specific to the Accord Hybrid's traction control system is the additional Creep Aid System, which prevents the vehicle from rolling backwards after a restart during idle-stop. Without creep aid, the brake actuators are released fully when a driver releases the brake pedal. Thus, slow foot movement from the brake to the accelerator could allow the vehicle to roll backwards if stopped on a hill. In the Accord Hybrid, however, the TCS system recognizes the idle-stop status and upon pedal release slowly reduces brake pressure from each of the wheels. In doing so, each brake caliper maintains a small amount of braking pressure until the driver accelerates the car.
The Civic Hybrid and Insight, hybrid-powered cars without traction control, controlled this rolling situation with a separate creep aid clutch attached to the CVT transmission. By incorporating the Creep Aid System into the Accord Hybrid's TCS, Honda was able to save weight and production costs.
Tires
Standard wheel size for the Accord Hybrid continues to be 16 inches, but wider 215/60 R16 tires surround each. The wider tires allows the Accord Hybrid, which weighs approximately 120 pounds more than an Accord EX V-6 and has 15 more horsepower, to maintain a larger contact patch for handling, steering and traction performance on par with the regular gasoline-only powered Accord V-6 Sedan.