Superstocks (previously known as A Grade Stockcars) are a premier class of New Zealand Speedway (dirt track racing).

Cars are of bespoke design with integral roll cages built to rules provided by Speedway New Zealand.

Superstocks weigh 1,400 to 1,500 kilograms (220 to 240 st; 3,100 to 3,300 lb) and are usually powered with modified production car engines of up to 248 cubic inches (4,060 cc).

Superstocks usually run engines such as Cars come in all different shapes and designs, varying from the ever-popular and successful Gordge chassis, through to the 'Tank" popularised by Dave Evans.

Another major meeting, is the annual New Zealand Superstock Teams Championship, run at Palmerston North International Speedway, in the first weekend of February.