Domestic car sales also declined marginally to 1,91,979 units compared to 1,92,845 in July 2017, according to data released by the Society of Indian Automobile Manufacturers (SIAM).
Motorcycle sales last month, however, rose 9.67 per cent to 11,50,995 units as against 10,49,478 units a year earlier.
Total two-wheeler sales in July rose 8.17 per cent to 18,17,077 units compared to 16,79,876 units in the year-ago month.
Sales of commercial vehicles were up 29.65 per cent to 76,497 units in July, SIAM said.
Vehicle sales across categories registered a rise of 7.97 per cent to 22,44,875 units from 20,79,204 units in July 2017, it added.