The UD Quon (kana: UD・クオン) is a heavy-duty commercial vehicle produced by the Japanese manufacturer UD Trucks.

Quon was originally developed by Nissan Diesel Corporation with the world first implementation of Selective catalytic reduction (SCR) system to an automobile.

[2] First Generation (2004-2017) Quon was released on November 18, 2004 in Japan, as the successor of BigThumb.

It is said that it was named for the term "Kuon (久遠)" with the same pronunciation, meaning "timeline forever" or "permanent".

[3] Quon engines using AdBlue Urea Selective Catalytic Reduction technology.