Excess diesel exhaust particles, multiplied by liters of fuel flowing through the cars over the years. (Edit:) The cars were allowed to emit a certain amount of

Excess diesel exhaust particles, multiplied by liters of fuel flowing through the cars over the years. (Edit:) The cars were allowed to emit a certain amount of dangerous substances, causing X amounts of deaths per year. Instead they in reality emitted a larger amount, and caused X + Y deaths per year. So VW traded Y number of deaths for extra marketshare and profit.