Mercedes-Benz ESP® Stability Control Mandated for All Cars

Safety Innovation Pioneered by Mercedes-Benz Dramatically Reduces Accidents

The U.S. Federal government is requiring ESP® stability control, a safety system pioneered by Mercedes-Benz, to be installed on all future cars. In making the announcement, the National Highway Traffic and Safety Administration (NHTSA) cited its analysis showing conclusively that cars equipped with stability control are 35 percent less likely to be involved in a collision.

Additionally, sport utility vehicles with stability control are involved in 67 percent fewer accidents than SUVs without the system. SUVs usually have a higher center of gravity, and ESP has been found to be especially effective in reducing rollovers.

NHTSA analyzed more than 40,000 collisions over a period of six years, focusing on similar vehicles with and without stability control. The dramatic results include similar reductions in fatal accidents as well. ESP-equipped cars had 30 percent fewer fatal crashes, and sport utility vehicles with ESP were 63 percent less likely to be in a deadly collision.

Now being used by other manufacturers, stability control systems reduce the likelihood of all fatal accidents by 43 percent and fatal single-vehicle crashes by 56 percent, according to another accident study by the Insurance Institute for Highway Safety (IIHS). When the IIHS recently updated the results of their 2004 accident study, they found that stability control provides even more life-saving benefits for SUVs.

Although the safety system provides significant benefits to both cars and SUVs, sport utility vehicles with stability control are reported to have 80 percent fewer rollovers than vehicles without the system. The study also concluded that the risk of all types of single-vehicle crashes in an SUV was reduced by 49 percent.

The NHTSA and IIHS analysis corroborates a Mercedes-Benz study from 2002 that revealed a 40 percent reduction in "loss of control" accidents after the company made ESP standard equipment on all models. Studies by other automakers and the University of Iowa found similar results.

ESP Stability Control Pioneered by Mercedes-Benz in 1995

After bringing the industry's first ABS anti-lock brakes and traction control systems to consumers in the 1980s, Mercedes-Benz collaborated with Bosch to invent ESP stability control and introduced it in 1995. The safety system made its debut on 1996 S-Class sedans and coupes, then became standard equipment on most models by the 2000 model year, and is standard on all Mercedes-Benz models today.

How Does Stability Control Work?

ESP can sense impending loss of control. The system works in a split second by braking individual wheels and/or reducing excess engine power, something that even the most skilled driver cannot do. ESP can be compared to having four individual brake pedals, one for each wheel, with a powerful computer to determine which pedal should be applied when and for how long.

The Mercedes-Benz ESP system helps drivers maintain stability, especially on slippery roads, by helping to prevent oversteer (rear-end "fishtailing") or understeer (front-end "plowing"). Even the "ESP" abbreviation helps underscore the system's benefits – it works invisibly, seemingly intuitively, to help keep the car going where the driver points it, when conditions might otherwise lead to loss of control and a possible accident without the system.

Using electronic sensors (primarily for yaw and lateral acceleration) and lightening-fast computer logic, the system constantly monitors a vehicle's actual path against its intended path. If there's any difference between what the driver is "asking" (primarily through the steering wheel) and what the vehicle is actually doing, the system brakes individual wheels to neutralize oversteer or understeer, even before the driver may sense any changes.

Other Safety System Use ESP

Both Active Lane Keeping Assist and Active Blind Spot Assist incorporate an intervention feature, in which ESP braking automatically helps correct the car's course if the driver doesn't heed the initial warning. Part of the optional DISTRONIC PLUS system, Active Lane Keeping Assist alerts the driver by simulating rumble strip vibration in the steering wheel if the car drifts from its lane without the turn signals on. it operates at speeds above 37 mph via a system that recognizes lane markings, thanks to a small camera in the windshield and a computer that analyzes the video images. DISTRONIC PLUS also includes Active Blind Spot Assist, which monitors both blind spots behind and to the side of the vehicle. Whenever a turn signal is activated with a vehicle in the blind spot, the driver gets visual and audible warnings.

AMG Torque-Vectoring Brake

AMG, the high-performance division of Mercedes-Benz has developed a Torque Vectoring feature for the ESP system to further improve handling on some of its models. Standard on the S63 AMG and S65 AMG, the Torque Vectoring feature corrects understeer during spirited driving or motorsports competition. When understeer or "plowing" is sensed during cornering, brief braking pulses at the inside rear wheel reduces understeer and improves active handling stability.

Three-Stage ESP

AMG and Mercedes-Benz have worked together to develop a three-stage ESP feature, which provides even more outstanding driving dynamics. With the "normal" ESP mode, the system senses understeer or oversteer and applies the brakes on one wheel to counteract the slide as on other Mercedes models.

In the "ESP Sport" mode, the driver can purposely slide the car to its limit of control before the system reacts, while in "ESP off," the system is fully turned off. Three-stage ESP is standard equipment on the SLS AMG, SL63 AMG roadster and the C63 AMG sedan.