Chrysler Hopes for Caliber Material Success

Chrysler Group is steeling its '07 Dodge Caliber against the rigors of crash testing by using materials new to the auto maker's lineup.

While the auto maker hopes this strategy improves the Caliber's chances of a high rating on front- and side-impact trials, including the demanding offset crash tests conducted by the Insurance Institute of Highway Safety (IIHS), the new materials also achieve significant weight reduction.

“The higher weight-to-strength ratio of high-strength steel allowed us to develop a body-in-white safety cage that meets more aggressive front-, side- and rear-impact requirements, but without the added weight of regular steel,” says Matt Liddane, chief engineer.

High-strength steel, which is featured extensively in the Caliber's front-end construction, has three times the tensile strength of standard steel. Hot-stamped steel is five times as strong.

Together, they account for 40% of the Caliber's total mass, the auto maker reveals. The use of hot-stamped steel, alone, in the vehicle's A- and B-pillars, as well as its roof-rail reinforcements, generates a 44-lb. (20-kg) decrease in overall weight.

The debut of the Caliber, which officially goes on sale Mar. 7 in North America, marks Chrysler's first use of hot-stamped steel in B-pillar construction.

The combined use of standard, high-strength and hot-stamped steel — integrated at strategic locations along the outboard rails, drivetrain tunnel, A- and B-pillars and the car's roof structure — are designed to “ride down” energy from an impact and minimize cabin intrusion, Liddane says.

The Caliber's pillar and roof construction also bolsters its resistance to crushing, he adds. In addition, the car features a magnesium-alloy, cross-car beam behind the instrument panel. Another cross-car beam, made of high-strength steel, is bolted atop the rear-seat riser of the 5-passenger vehicle.

Concealed beneath the rear seat, the beam is about the width of a hand from the vehicle's edge. But Chrysler bridges this span with hard foam built into the rear-door panel.

“In the event of a side-impact event, it will carry the load across the car instead of what, unfortunately, normally happens, which is intrusion,” Liddane says.

Designed to take up to 60% of the load from a side-impact crash, the rear-seat beam's performance is supplemented by steel beams inside the rear doors. The same beams also are present in the front doors.

Chrysler also advances the application of hydroforming with the Caliber's introduction. It marks the first time hydroformed front closures and upper cross members have been used in high-volume compact-car production.

Until recently, these components were relegated solely to trucks and SUVs. But improved processes enable the production of smaller diameters required for compact vehicles. Chrysler engineers then use to their advantage the technology's capacity to manufacture complex shapes.

The Caliber's hydroformed components snake around the engine compartment, providing mounting points for its radiator module.

The unique shape also adapts easily to the requirements of the Caliber's sister vehicles — the Jeep Compass and yet-to-be-confirmed Jeep Patriot, sources say.

Without making predictions, Chrysler has high hopes for the Caliber when it is subjected to crash-test rating systems by the IIHS, National Highway Traffic Safety Admin. and Consumer Reports magazine, says Judith K. Wheeler, DaimlerChrysler Canada's marketing vice president and former director-Dodge car marketing and front-wheel-drive product planning.

The Caliber also marks several Chrysler “firsts” with regard to restraint systems and chassis electronics.

It is the first Chrysler compact car to feature standard side-curtain airbags and electronic stability control, and Chrysler's first passenger car to offer an electronically controlled all-wheel-drive system.