FORT WORTH, Texas - Motorcoach operators ordering new MCI J4500s in the days and weeks ahead will take delivery of a coach that is markedly different at its core -- with new axles, independent suspension, brakes and air system -- than previous J-models.

MCI is unveiling the new components and systems on its most popular coach at a series of customer events, called Reliability Rallies, taking place across the U.S.

The first was conducted here at the Texas Motor Speedway, site of the 2014 Duck Commander 500 NASCAR Sprint Cup Series stock car race.

The venue was perfect for both explaining, highlighting and demonstrating the new features even if the sleek 700-horsepower NASCAR machines were long gone.

The rallies continue at auto race tracks and major sports stadiums through the rest of this spring and summer, with the next one June 4 at Gillette Stadium in Foxboro, Mass. The second rally was May 22 at Chicagoland Speedway in Joliet, Ill.

The MCI events feature both technical and under-the-coach briefing sessions; test rides; supplier and sponsor representatives and booths, and lunch.

Also part of the activities are ride alongs and familiarization briefings on the new two-door Setra S 417 Top Class coach, a display of new and used coaches, and MCI-Setra parts and service promotions.

"We wanted to bring the product to the customers," said MCI Executive Vice President Patrick Scully.

The heart of the events, however, is the showcasing of one of the dozen test-bed MCI J4500s that have been outfitted with new ZF axles and independent suspension systems, new Bendix ABD 22X brakes, and an upgraded air system that is said to be more efficient and reliable.

The benefits of the ZF independent front suspension on the J4500 are multifaceted and pronounced.

The turning radius -- with the standard, passive steering ZF tag axle -- has been reduced from 45 feet to less than 41 feet. The reduction is achieved through a sharper front-wheel cut and a tag axle that offers 10 degrees of steering.

MCI says operators should see reduced tire wear because of the standard passive rear-steer tag and automatic tag axle.

The independent suspension system also provides a smoother and quieter ride with improved stability, bump isolation and driver comfort.

"It has fantastic driving behavior," said a ZF technical service manager.

The system uses made-in-the-USA parts, offers improved serviceability and has fewer components, according to ZF and MCI executives.

Both the independent front and drive axles require less maintenance than the axles they replaced, said one ZF engineer.

And, importantly, the system weighs less. The J4500 gains a 700-pound payload increase with the ZF and Bendix systems.

The ADB22X Bendix brakes mounted on the new ZF axles are designed to not only provide shorter, safer braking but do it with a passenger car-like brake pedal feel. This is achieved via an "optimized friction couple," says Bendix.

The ADB22X uses a two-pin floating caliper design that has fewer components than four-pin air disk brakes, improving serviceability, reducing weight, and offering more precise brake adjustment.

The brake has integrated pad- and rotor-wear sensing, and has common brake rotors.

The MCI J4500 is delivered with the Bendix electronic stability program that improves vehicle control, especially in challenging driving situations, including those where a rollover is possible.

The system appropriately intervenes during untoward driving events, reducing engine torque and, if needed, applying the correct pressure to the brake system.

A new option for the J4500 is the Bendix Wingman, which provides adaptive cruise control and collision mitigation functionality.

The system monitors a coachs position behind other vehicles and automatically reduces throttle or applies the brakes to maintain safe following distances when the driver does not act.

The Bendix Wingman system is said to be the only collision mitigation technology delivering active braking, stationary object alerts, "always-on" driver alerts, potential fuel economy improvements, and helpful data outputs.

The upgraded J4500 air system speeds coach rise times and has fewer connections, meaning greater reliability, says MCI.

Combined with the MCI "dynamic suspension system," the air system allows lower kneeling and faster recovery.

To test the new systems on the J4500, MCI used the Bosch automotive test track near South Bend, Ind., where an independent team simulated nearly one million miles of driving.

Additionally, MCI has nine J-coaches, featuring the ZF and Bendix systems, in field tests with larger operators across the U.S.

The first production models with the new systems and components are expected to roll off the assembly line in September.

MCI D-series coaches are to get the same system, but without the independent front-wheel suspension.

The other MCI rallies and test drives will be June 11 at the Sands Resort & Casino in Bethlehem, Pa.; June 26 at Atlanta Motor Speedway in Hampton, Ga., and July 8 at AT&T Park in San Francisco.

Each event runs from 9 a.m. to 3 p.m. Learn more at www.mcicoach.com.