ESP saves lives...
Off during any kind of racing wether it be drag, track, or autocross.
I had it on on accident ontime and ran 4 secs slower during an autocross.
ESC compares the driver's intended direction in steering and braking inputs, to the vehicle's response, via lateral acceleration, rotation (yaw) and individual wheel speeds. ESC then brakes individual front or rear wheels and/or reduces excess engine power as needed to help correct understeer (plowing) or oversteer (fishtailing). ESC also integrates all-speed traction control, which senses drive-wheel slip under acceleration and individually brakes the slipping wheel or wheels, and/or reduces excess engine power, until control is regained. ESC cannot override a car's physical limits. If a driver pushes the possibilities of the car's chassis and ESC too far, ESC cannot prevent a crash. It is a tool to help the driver maintain control.
ESC combines anti-lock brakes, traction control and yaw control (yaw is spin around a vertical axis).
Numerous international studies have confirmed the effectiveness of ESC in helping the driver maintain control of the car, help save lives and reduce the severity of crashes. In the fall of 2004 in the U.S., the National Highway and Traffic Safety Administration confirmed the international studies, releasing results of a field study in the U.S. of ESC effectiveness. NHTSA concluded that ESC reduces crashes by 35%. The Insurance Institute for Highway Safety (IIHS) later issued their own study that concluded the widespread application of ESC could save 7,000 lives a year. In June 2006, the IIHS updated the results of their 2004 study by stating that up to 10,000 fatal crashes could be avoided annually if all vehicles were equipped with ESC. That makes ESC the greatest safety equipment development since seat belts, according to some experts. The European New Car Assessment Program (EuroNCAP) "strongly recommends" that people buy cars fitted with stability control . On November 21, 2006 the IIHS announced that 13 of the 2007 vehicles had earned their TOP SAFETY PICK rating--- a major new requirement for this top rating is that the vehicle must be equipped with ESC However, some people contend (backed up by the theory of risk compensation) that the perception of safety conferred by the ESC will encourage more dangerous driving, as seems to be the case with seat belts. Among those concerned that ESC is just the latest example of a long and ultimately unsuccessful campaign, in the U.S. and abroad, to make cars that are capable of compensating for dangerous driving behaviour is the Partnership for Safe Driving www.crashprevention.org
. The Partnership believes that if no corresponding effort is made to deter speeding, aggressive, distracted and drowsy driving, this technology will not live up to its promise and may, in fact, encourage even more dangerous driving behaviour.
Some driving enthusiasts, most publicly motoring journalists from enthusiast magazines, object to some of the implementations of ESC. They contend that by making it impossible to explore the dynamic behaviour of their cars, overzealous ESC systems spoil much of the fun of driving. Consequently, some manufacturers allow drivers to disable ESC systems, and/or use ESP systems that allow greater levels of under or oversteer before it intervenes. Some even provide a setting so the user can choose whether the system will intervene earlier or later stage. Enthusiasts have also begun to modify ESC systems to suit their preferred driving styles .
It has also been argued that ESC is being used as a "catch all" for poorly designed cars, whereby the basic mechanical handling of a car is unstable and ESC is used to compensate for the problem, like in the first version of Mercedes-Benz A-Class that failed the moose test and to fix this, every A-Class was retrofitted with ESC.
Another point of critique is that in the case of very dangerous drivers, the car will be able to be pushed further (and faster) before the limits of the vehicle and ESC are reached, meaning that should the vehicle become "out of control" this will happen at higher speeds, leading to more severe crashes.
In the event that the vehicle is out of alignment or has a tire with low enough air pressure to affect the steering wheel's angle, the yaw rate sensor would conflict with the steering wheel sensor. If this were the case, the vehicle's Powertrain Controle Module may interpret the driver's actions as trying to turn the vehicle, rather than compensation for a mechanical problem. However, ECU programmers are familiar with this type of issue, and use cross-correlation between sensors to identify problems.