 The values assigned to serious burn injuries and loss of life were based on values calculated by NHTSA in 1972.In the memo Ford estimated the cost of fuel system modifications to reduce fire risks in rollover events to be $11 per car across 12.5 million cars and light trucks (all manufacturers), for a total of $137 million.The design changes were estimated to save 180 burn deaths and 180 serious injuries per year, a benefit to society of $49.5 million.