In the previous entry, we looked at the performance of the Mod Rod and how many cars you would have to test to find a really fast example. In this case, I wanted to look at the 2019 Kia Stinger GT which has a reputation as a fast racer. It is an ideal wheel candidate because it is a bit of a peg hanger and has had four color variations in the last year. I was able to find twelve examples, three from each color, in a single trip.
I ran these down my sixteen foot track with a timer. Each car makes three runs and the runs are averaged.
A majority of them were below 1.7 seconds, which is a good sign. The average speed of 1.694 seconds was significantly faster than that of the Mod Rod’s 1.724. But is that the full story? I noticed two of the three blue examples (the oldest), were significantly slower. Is that a coincidence? In statistics there is the concept of an “outlier”, a data element that is significantly different from the others. This is best shown using a “box plot”, which shows where the majority of the data falls, and if there are outliers. Here is an example from a great article by Michael Galarnyk:
If we plot our data, along with the previous Mod Rod data as a Box Plot, a story emerges:
It shows that indeed, the two slower examples are outliers. The date code “N20” indicates the car was manufactured in May of 2020, almost 15 months previous. Does sitting on a store shelf make the car slower? Corrosion on the axles? The other clue that would support this theory is that the three fastest examples all came from the cars made in March 2021, which makes them only 5 months old. That bears further exploration if any of you are taking statistics or know someone who is, but I wanted to move on to another question. How would graphite affect the performance, and would the result vary based on the original performance?
I picked three examples, the fastest (#11), the slowest of the non-outliers (#6), and the slowest (#3). They each received a single application of the Hobby Lube graphite using my normal method and ran again three times, with the average time being shown.
Wait, what? Graphite caused the fastest car to slow down a fraction, while significantly speeding up the other cars? Again, a chart is helpful in seeing the picture:
So, in summary, the 2019 Kia Stinger is a fast casting in comparison to the Mod Rod, but the data indicates that sitting on the shelf is detrimental to performance. The data also indicates that application of graphite has the greatest effect on the slower cars. So many questions in the quest for the Golden One!
Tune in next time when we will look at the Honda Civic Si.