Why do good cars have low resale values?

Low resale values can result from a number of different things, some not related to how "good" a car is. For instance, right now, SUVs and trucks with poor gas mileage have low resale values. Resale values on used cars also drop when car makers put large incentives and rebates on brand new cars of the same make and model. However, low resale values usually reflect the overall quality and reliability of a car.