The word "positraction" is a term that can be traced back to the auto industry of the 1950's and 1960's. It was devised by manufacturers as a term to refer to limited slip differential. The term was made famous by Chevrolet and is also referred to as "posi" or "positrac". To know if your car has this feature installed try referring to the information available specifically covering the make and model of the vehicle you are driving.
The feature may be referred to as a "positraction"in the case of Chevrolet vehicles, a "safe-t-trac" in the case of Pontiacs, "Twin-grip" in the case of the American Motors Company, "Sure Grip" in the case of Mopar, Trac-lock or Equa-lock in the case of Ford, E-Diff in Ferrari, Hydratrak in the case of TVR and Viscodrive in the case of Fiat. These names are manufacturer specific and one may simply see the feature referred to as limited slip differential.
The feature may be referred to as a "positraction"in the case of Chevrolet vehicles, a "safe-t-trac" in the case of Pontiacs, "Twin-grip" in the case of the American Motors Company, "Sure Grip" in the case of Mopar, Trac-lock or Equa-lock in the case of Ford, E-Diff in Ferrari, Hydratrak in the case of TVR and Viscodrive in the case of Fiat. These names are manufacturer specific and one may simply see the feature referred to as limited slip differential.