 The clutch of all IndyCar Series cars are carbon with steel housing 3-plate clutch operated by foot-pedal in 1996–2011 later hand-paddle steering wheel clutch in 2012–present and provided by AP Racing.Mechanical limited-slip differentials are also allowed and constant velocity joint tripod driveshafts are also used.All IndyCar Series car drivetrains are currently rear mid-engine with rear-wheel-drive layout.