Undersquare refers to the relative size of the bore and stroke dimensions of an engine.

An undersquare engine has a larger stroke than bore diameter. Most modern engines have larger bores than strokes, so are oversquare.


Understeer is when a vehicle does not turn in to a corner as much as the driver expects, and instead runs wide.

Understeer is caused by a loss of grip at the front wheels compared to the rear.

Most cars are set up to understeer at the limit, as this is a stable handling condition which most drivers can easily cope with – unlike oversteer.

In the USA, understeer is often called push.

Compare oversteer.