The weight to power ratio (power loading) of a 2000 SAAB 9-5 is 22 pounds per horsepower.
To find the weight to power ratio of a car you divide the weight of the car by the horsepower of the car. You want the number to be as small as possible and these numbers can be used as a tool to better compare the performance of two vehicles. This is not to say that the number is the best way to compare vehicles, just more balanced than looking at hp numbers alone. Obviously everything from tires to transmission affect a car's performance and aren't taken into account with this number.
The 2000 9-5 has a curb weight of 3730 pounds and 170 horsepower. 3730/170=21.9
The 2007 9-5 has a ratio of 13.35.
Comparison of current vehicle weight to power ratios