Understeer and oversteer are vehicle dynamics terms used to describe the sensitivity of the vehicle to changes in steering angle associated with changes in lateral acceleration. This sensitivity is defined for a level road for a given steady state operating condition by the Society of Automotive Engineers (SAE) in document J670[1] and by the International Organization for Standardization (ISO) in document 8855.[2] Whether the vehicle is understeer or oversteer depends on the rate of change of the understeer angle. The Understeer Angle is the amount of additional steering (at the road wheels, not the hand wheel) that must be added in any given steady-state maneuver beyond the Ackermann steer angle. The Ackermann Steer Angle is the steer angle at which the vehicle would travel about a curve when there is no lateral acceleration required (at negligibly low speed).
The Understeer Gradient (U) is the rate of change of the understeer angle with respect to lateral acceleration on a level road for a given steady state operating condition.
The vehicle is Understeer if the understeer gradient is positive, Oversteer if the understeer gradient is negative, and Neutral steer if the understeer gradient is zero.
Car and motorsport enthusiasts often use the terminology informally in magazines and blogs to describe vehicle response to steering in a variety of manoueuvres.
^SAE International Surface Vehicle Recommended Practice, "Vehicle Dynamics Terminology", SAE Standard J670, Rev. 2008-01-24
^International Organization for Standardization, "Road vehicles – Vehicle dynamics and road-holding ability – Vocabulary", ISO Standard 8855, Rev. 2010
and 23 Related for: Understeer and oversteer information
Understeerandoversteer are vehicle dynamics terms used to describe the sensitivity of the vehicle to changes in steering angle associated with changes...
same speed. This is known commonly as lift-off oversteer. Understeer is also a result of wheelspin and traction loss. It results in a vehicle not being...
highlight understeer or oversteer of the chassis. Next was "Hammerhead", a left-then-right corner, which again highlighted understeerandoversteer. The track...
cause understeer or oversteer to occur more easily than if body roll was not a factor. Body roll can also be uncomfortable for passengers and cause damage...
Proper seat and hand position Looking ahead Straight line braking Brake point Turn in point Apex Track out point Understeerandoversteer Although the...
driven wheels will lose traction and slide sideways. This occurs as understeer in front-wheel-drive vehicles andoversteer in rear-wheel-drive vehicles....
vibration, and harshness Pitch Ride quality Roll Speed wobble Understeer, oversteer, lift-off oversteer, and fishtailing Weight transfer and load transfer...
individually, such as the outer front wheel to counter oversteer, or the inner rear wheel to counter understeer. Some ESC systems also reduce engine power until...
steady-state cornering, front-heavy cars tend to understeerand rear-heavy cars to oversteer (Understeer & Oversteer explained), all other things being equal...
greater than 1:1, the vehicle will tend to understeer, while a ratio of less than 1:1 will produce oversteer. Actual instantaneous slip angles depend on...
his car to yearn from understeerandoversteerand was 19th. The two Arrows of Enrique Bernoldi and Jos Verstappen were 20th and 21st; Verstappen droveArrows'...
rear or front wheels slip sideways (during oversteerandundersteer). Controlling oversteer - During oversteer, the rear end of the vehicle will spin out...
especially over a single lap. He shared his father's preference of oversteer over understeerand lacked a flamboyant driving technique. Rosberg's qualifying...
force (400 N). Likewise, a car may oversteer or even "spin out" if there is too much force on the front tires and not enough on the rear tires. Also,...
issues, causing it to switch between excess understeerandoversteer. Fisichella, 15th, said understeerand poor grip prevented him from lapping faster...
anticipated by the driver, roll understeer. It is possible to design a rear live axle suspension that exhibits roll oversteer but it is highly undesirable...
lighter bumpers and wings (fenders), or none at all. Car handling Car tuning, the hobby of modifying a car Coil bind OversteerUndersteer Vehicle dynamics...
system Oversteer, more prone to happen with a rearward-biased brake balance, i.e. greater braking force on the rear wheels Regenerative brake Understeer, more...
measure of the characteristics of a vehicle that govern its understeer balance. The understeer is measured in units of degrees of additional yaw per g of...
flick is a technique used predominantly in ice racing and rallying. The technique induces oversteer using weight transfer to carry a vehicle through a turn...
sudden transition from understeer to oversteer may be startling for some people. The car is infamously known for its "snap-oversteer" phenomenon. This notoriety...
Global Information