Honda Automobiles: 2015 Honda Fit

The new-from-the-ground-up 2015 Fit has been improved in every aspect, starting with the body structure. New designs produced with new manufacturing techniques result in a lighter but stronger platform, tighter body tolerances and a quieter cabin. While the length of the Fit has been reduced by 1.6 inches, the wheelbase has been lengthened by 1.2 inches to improve interior space and ride quality.

Key New Body Features

  • Next-generation Advanced Compatibility Engineering™ (ACE™) body-structure
  • Advanced body and door manufacturing techniques
  • Shorter overall length, by 1.6 inches
  • Longer wheelbase, by 1.2 inches
  • Increased width, by 0.3 inches
  • Lighter, more rigid platform
  • Improved body sealing and noise insulation

Advanced Compatibility Engineering™ (ACE™)
The 2015 Fit utilizes the next-generation version of Honda’s proprietary Advanced Compatibility Engineering™ (ACE™) body-structure technology to enhance occupant protection and crash compatibility in frontal collisions. ACE utilizes a network of connected structural elements-with an improved design and a greater use of high-tensile strength steel-to distribute crash energy more evenly throughout the front of the vehicle. This enhanced frontal crash energy management helps to reduce the forces transferred to the passenger compartment and can help to more evenly disperse the forces transferred to other vehicles in a crash. It is expected to help the Fit achieve excellent ratings in crash testing by the IIHS and the NHTSA. ACE also helps minimize the potential for under-ride or over-ride situations that can happen during head-on or offset frontal impacts with a larger or smaller vehicle

Unlike most conventional designs that direct frontal crash energy only to the lower load-bearing structures in the front end, ACE actively channels frontal crash energy to both upper and lower structural elements, including the floor frame rails, side sills and A-pillars. By creating specifically engineered “pathways” that help distribute these frontal impact forces through a greater percentage of the vehicle’s total structure, ACE can more effectively direct those forces around and away from the passenger compartment to help limit cabin deformation and further improve occupant protection. And like other Honda models, the Fit has an impact-absorbing front body design to help attenuate energy in the event of a frontal collision with a pedestrian.

Weight Reduction
Since moving the mass of a vehicle requires energy, overall fuel efficiency can be improved by reducing its weight. Reducing vehicle weight must be balanced with other factors such as structural integrity; ride and handling characteristics; low noise, vibration and harshness (NVH); and occupant safety.

In the 2015 Fit, weight reductions include the extensive use of super-high-tensile strength steel that provides increased structural strength with less material. With 27 percent of the body structure being made with these high-grade steels – 780 megapascals of higher yield strength – the body is 44 pounds lighter than the previous Fit’s body. An additional 6.6 pounds in total is shaved from the weight of the doors with a manufacturing process that integrates the door outer skin, inner panel and sash, press-forming them together. A further 8.8 pound reduction in body weight was realized from the inner frame and body assembly process.

The Fit’s proprietary Advanced Compatibility Engineering™ (ACE™) body structure is constructed with high-tensile steel and hot-stamped steel reinforcements and stiffeners. Improved designs and efficient manufacturing processes simplify production while improving strength and reducing weight. These include suspension mounting points with better lateral stiffness, and a new floor structure with a high-efficiency load-path. A new pressed door construction technique to combine the outer skin, inner panel and sash use fewer components and eliminates the need for welding and the use of a sealer. To assist in creating more rear passenger room and to provide a larger rear door opening, the rear wheel arch was redesign to reduce the distance between the door opening and arch flare and to eliminate the need for spot welding between the body and inner arch.

Noise mitigation
Great efforts were made to target class-leading quietness in the new Fit, especially upon engine start-up, acceleration and on rough roads. Rather than just masking sound, the improved stiffness of the frame allowed for tighter tolerances in the body for better sealing. The new press-formed door construction technique also improved sealing. A reduction in firewall panel openings and gap reduction improves engine noise isolation. Furthermore, soundproofing material is used extensively throughout the body, including in the ceiling, doors, fenders, and floor, and in the dash, instrument panel and center console.

Body Features