Are you looking to downgrade to v1.40 to use a or because of hardware performance ?
: Once selected, Steam will automatically begin downloading the files for version 1.40. The game title in your library will now show [temporary_1_40] Legacy (Non-Steam) Download Links euro truck simulator 2 v140 better download link
For players looking to update their game, Euro Truck Simulator 2 (ETS2) version 1.40 Are you looking to downgrade to v1