Jeff took a look at my comparison post and asked about the units for the slalom course. I knew it was MPH but Jeff reasoned that time through the course might be a better value to track. I figured that average speed was used because different cars will have different acceleration rates, times through the course, speeds and more. Just using time might be a better indication of cornering ability and power, not just cornering ability. Anyway, I found this in one of my Motor Trend articles:

Just drive around the cones as fast as your can, right? Yes-and no. Try cracking off six perfect, consecutive, emergency lane-changes at freeway speeds (some well above) with a margin of error at less than one inch. Sure, this sound challenging until one realizes each cone arrives at less than a one second interval-the whole thing takes less than six seconds in these vehicles. This is one test that best reveals a car’s evil side. A propensity to push, get loose, or even spin is ever more apparent while all four ties are howling at, in some cases, 80 MPH. That’s right, the speeds listed above are timed averages between the entry and exit markers along the 600-foot course-not how fast the car is actually traveling along its curvy line, which is, in fact, much faster.