The OICA, or  Organisation Internationale des Constructeurs d'Automobiles (International Organization of Motor Vehicle Manufacturers), tracks and represents the global auto industry. Here is a raw summary of the heavy truck production for 2017 to 2018 by countries.

China, Japan and India remain the top three respective heavy truck producers for 2017-2018 and account for more than 70% of the global production of heavy trucks.

In 2018, there are close to 4.2 million heavy trucks produced. Out of which,50.3% (or 2.1 million heavy trucks) are produced in China, 12.2% (or 0.5 million heavy trucks) are produced in Japan and 9.6% (or 0.4 million heavy trucks) are produced in India.

In 2017, there are close to 4 million heavy trucks produced. Out of which, 55% (or 2.2 million heavy trucks) are produced in China, 12.6%  (or 0.5 million heavy trucks) are produced in Japan and 7% (or 0.3 million heavy trucks) are produced in India.

(Note: some figures may be rounded off; listed figures have not been adjusted for double-counting across countries)