2013 Honda Fit EV: Chassis
6/29/2012 1:57:00 PM
The Fit EV 's smooth ride, nimble handling and a solid, connected-to-the-road feel starts with its rigid steel unit body, with build strength that enables highly precise suspension operation. Starting with this precision platform, engineers then optimized the MacPherson strut front suspension and added a rear multi-link system in place of the Fit and Fit Sport 's H-shaped torsion beam rear suspension. The revised systems accommodate the additional weight of the battery pack, while still ensuring a comfortable ride and stable handling.
An electrically power-assisted hydraulic braking system utilizes 11.1-inch ventilated front discs and 8.7-inch rear drums, along with a new electric servo brake system that helps to recharge the lithium-ion (Li-Ion) battery pack while the vehicle is coasting or braking. Electric Power Steering (EPS) is standard.
The Fit EV is equipped with low rolling-resistance P185/65R15 M+S all-season tires with 15x6.0-inch, five-lug aluminum alloy wheels featuring a unique five-spoke design. A Tire Pressure Monitoring System (TPMS) is standard. A flat repair kit, stored under the cargo area floor lid, eliminates the need for a spare tire, allowing extra room for the under-floor Li-Ion battery pack.
The Fit EV 's electronic systems are just as impressive as the mechanical ones, with Electric Power Steering (EPS), electrically power-assisted hydraulic and regenerative braking systems, ABS with Electronic Brake Distribution (EBD) and Brake Assist, and Vehicle Stability Assist (VSA®) with Traction Control all standard.
Standard chassis features
- MacPherson strut front suspension
- Independent multi-link rear suspension
- Electric Power Steering (EPS)
- Electrically power-assisted hydraulic and regenerative braking systems
- ABS with Electronic Brake Distribution (EBD) and Brake Assist
- Vehicle Stability Assist (VSA®) with Traction Control
- 15-inch alloy wheels
- Lightweight aluminum front subframe
- Tire Pressure Monitoring System (TPMS)
MacPherson Strut Front Suspension
The Fit EV features MacPherson strut front suspension for outstanding space efficiency, a smooth ride, nimble handling, and excellent noise, vibration and harshness isolation. Precise geometry and specially tuned spring, damper and bushing rates provide a balance of responsiveness, comfort and solidity that makes the Fit EV confidence-inspiring as well as fun to drive.
Multi-Link Rear Suspension
Whereas the Fit and Fit Sport use an H-shaped torsion beam rear suspension, the Fit EV has a rear independent multi-link system designed to accommodate the addition weight of the Li-Ion battery pack. The system fits compactly underneath the rear seating and storage area while providing excellent ride and handling characteristics, along with low NVH.
Electric Power Steering (EPS)
Working in conjunction with the MacPherson strut front and independent multi-link rear suspension systems, the Fit EV 's rack-and-pinion Electric Power Steering (EPS) provides firm, direct and precise response. The result is confidence-inspiring steering at all speeds. The Fit EV 's steering ratio is slightly slower than in the gasoline-powered Fit to retain favorable steering effort with the added weight of the Fit EV 's battery pack.
The Fit EV is equipped of 11.1-inch ventilated front disks and 8.7-inch rear drum brakes powered by a new electric servo brake system. Sensors at each wheel send signals to the brake-control module, which can modulate braking pressure based on individual wheel speed, optimizing brake pressure balance, while providing a linear pedal feel. Electronic Brake Distribution (EBD) adjusts front-to-rear brake pressure according to vehicle load distribution for optimum brake balance at all times.
The Fit EV also includes a 4-channel anti-lock brake system (ABS) with Brake Assist. ABS independently modulates braking power at each wheel to help the driver retain steering control during heavy braking, while Brake Assist recognizes emergency braking situations and almost instantly helps the driver apply full braking force. (See Safety section for more information).
Electric Servo Brake System: Advantages
The Fit EV is the first Honda to use an electric servo brake system. Through cooperative control between the mechanical brakes and regenerative braking, it allows a 5-percent higher energy recovery rate than conventional regenerative braking systems. Compared to a conventional hydraulic pressure booster, the new system offers a faster response and highly accurate fluid-pressure control. This results in a smoother, more linear and natural brake pedal feel. Cooperative control between the mechanical brakes and regenerative braking translate into energy recovery over a broader range from initial braking all the way to immediately before the vehicle stops.
Two different illuminated warnings in the instrument panel alert the driver in the event of a service need in either system. A red Brake Warning Indicator illuminates if servicing is required in the conventional hydraulic or manual parking-brake systems, or if the parking brake is left on inadvertently. An amber indicator illuminates if there is a service need in the regenerative braking system.
Vehicle Stability Assist (VSA®) with Traction Control
VSA® is an Electronic Stability Control system that helps enhance control capability while the vehicle is accelerating, braking, cornering or when the driver makes a sudden maneuver. (See Safety section for more information.)
Wheels & Tires
The Fit EV features P185/65R15 M+S low rolling-resistance tires mounted on lightweight 15x6.0-inch five-spoke alloy wheels. The tires are 10mm wider and the wheels are 0.5-inch wider than on the gasoline version Fit to support the additional weight of the Fit EV battery pack. In addition, the Fit EV wheels use five lug bolts vs. four lug bolts on the regular Fit wheels.
Tire Repair Kit
A flat repair kit eliminates the need for a spare tire. Consisting of a special sealant canister and 12-volt compressor powered by the accessory power port on the center console, the flat-repair kit is designed to allow temporary repair of small punctures in the tread area of a tire, and allows the vehicle to be driven at up to 50 mph to reach a qualified service station for a more permanent repair. The kit is stored under the cargo area floor lid.
Tire Pressure Monitoring System (TPMS)
The Fit EV includes a Tire Pressure Monitoring System (TPMS) that alerts a driver whenever the air pressure in one or more of the vehicle's tires is significantly below the recommended level. (See Safety section for more information.)
Lightweight Aluminum Front Subframe
The Fit EV adopts a lightweight aluminum front subframe. It combines a squeeze die-cast part with a pressed aluminum panel welded using a friction stir method. The result is a highly rigid yet lightweight subframe structure.