• General Motors average gross margin for 2011-09-30 was 0%, a 0% decline from 2011-12-31.
• General Motors average gross margin for 2011-12-31 was 0%, a 0% decline from 2012-03-31.
• General Motors average gross margin for 2012-03-31 was 0%, a 0% decline from 2012-06-30.

Gross margin can be defined as a company's total sales revenue minus its cost of goods sold, divided by the total sales revenue, expressed as a percentage.