New Suspension Requirements - FMVSS 126 Decoded

How federally mandated stability control affects your truck

If you are a sharp-eyed reader you might have noticed ads in this magazine recently touting aftermarket suspension manufacturers’ compliance with Federal Motor Vehicle Safety Standard 126 (FMVSS 126), but you might not know exactly what that means. FMVSS 126 requires electronic stability control (ESC) on all new vehicles under 10,000 pounds GVW. The National Highway Traffic Safety Administration estimates that ESC will reduce single-vehicle crashes of passenger cars by 34 percent and single vehicle crashes of SUVs by 59 percent, with a much greater reduction of rollover crashes.

But all of a sudden adding a suspension kit and big, aggressive tires isn’t as easy as it used to be. Several of the top suspension manufacturers in the country stepped up to the plate, though, to demonstrate that their products can live in harmony with ESC systems, but it wasn’t particularly cheap nor easy to do so.

“All of a sudden adding a suspension kit and big, aggressive tires isn’t as easy as it used to be”

Pro Comp was one of the first companies to pioneer this testing back in 2009 when GM released the GMT900 truck platform. “We learned right away how small changes could have huge effects on the ESC,” explained Pro Comp marketing manager Mark Mathews. Pro Comp’s parts are often installed by new car dealers, so Pro Comp wanted to provide assurance that its products would not adversely affect the ESC systems. Since 2009, Pro Comp has certified the Ford F-150, the new Silverado, the Jeep Wrangler JK, and most recently the Toyota Tundra.

BDS Suspension is another company that has aggressively tested its products, certifying the Ford F-150, Ram 1500, GM 1500, and Jeep JK kits in a variety of lift heights. “Our goal is to test each and every applicable suspension kit,” revealed Glen Hard, COO of BDS’s parent company Sport Truck USA. “These new regulations will help weed out some of the kits/manufacturers that produce subpar products.”

Forward-thinking suspension manufactures see this as an opportunity to innovate. “It isn’t just marketing hype; some trucks will simply be undriveable if they are not engineered right,” said Mathews. “Before anything goes to the certification there is a lot of R&D done at our in-house facility with computer modeling, then testing the dirt and on the street.”

All that research results in a better product for the consumer, who can confidently lift their new truck without concern.

What About Tires & Wheels?
One thing you might have noticed when different suspension manufacturers are touting their certifications is that they tell the tires and wheels the test was performed with. Wheel offset, tread pattern, and section width all have a large influence on how the ESC reacts. The further you get away from the stock parameters, the more dramatic the results. Suspension manufacturers can’t test every possible tire and wheel combination, but choosing wheel offsets and tread patterns close to what was tested would be wise.

Check out the video below to see Pro Comp's Silverado in action during FMVSS 126 testing!