Mahindra & Mahindra Ltd on Thursday said its total vehicle sales grew 15 per cent year-on-year to 73,944 units in January. The utility vehicle sales stood at 43,068 units in the previous month as against 32,915 vehicles sold in January last year, growing 31 per cent year-on-year, M&M Ltd saidThe commercial vehicle domestic sales during the month under review stood at 23,481 units.