How Many 991 GTS Coupes are Identical to My Car?
After discovering that my 997 GTS is rare, I started to wonder about my 991.1 GTS. While the data was readily available to analyze the former, this just wasn’t the case for the later. Total production stats have been shared, but you need the build data to really hone in.
The eureka moment came one afternoon. I could use sampling to draw a more detailed profile of the population of 1,245 US 991.1 GTS coupes.
A quick refresher on statistics showed that I’d need details on ~65 cars for a confidence level of 90% and a margin of error of 10%, the lowest statistically acceptable ranges in the tool that I used to calculate a sample size.
Next, I used a random number generator to arrive at a range of VINs and set off to do the ‘pick & shovel’ work at VIN Analytics, manually entering VINs until I found enough GTS coupes to run the analysis. This proved to be quite tedious after only a few attempts.
Before slipping too far down that slope, I reached out to the team at VIN Analytics and explained what I hoped to accomplish. Thankfully they offered to send me a data set so I could sidestep looking for the needles in the haystack! (Add their site to your favorites. It provides a wealth of data on Porsche cars, and they are all-around great guys!)
With the tedious work aside, I flexed the spreadsheet muscles (e.g. =INDEX,=COUNTIF) to run the analysis.
Let’s start with a question that always seems top of mind: the ratio of manual transmissions to PDK. Color me surprised as only 53% of the cars in the sample were delivered with a PDK transmission. I expected the mix to be more consistent with the 997 GTS.
The data for 991.1 cars only includes coupes, while the 997 data includes all models. It’s pure speculation, but perhaps the inclusion of cabriolets in the 997 mix increases the portion of PDK cars.
Next up on the analysis is color, and another surprise. My 991 GTS is a Voodoo Blue PTS car, and I expected that option to be a rare choice. The data shows something different.
The sample data set included a Rennsport Reunion car and a few Club Coupes. The build sheets list these packages as PTS cars, but they are somewhat different than a traditional PTS car IMHO. The factory chose them, not the buyer. If we exclude these cars from the analysis on color, then PTS drops to ~5% of the sample.
One other surprise on color is the relatively low number delivered in black; roughly 7% of the 991.1 cars (i.e. Jet Black Metallic + Black) vs. a third of the 997 GTS generation.
With transmission and color settled, next I looked at a set of the options on my car.
As I learned with the 997 GTS analysis, it’s the small things that make these cars unique. Not surprisingly, my car was the only one in the sample with the Sport Chrono Clock Dial in Racing Yellow.
Similarly, it’s the only car in the sample with both SportDesign and a rear wiper.
In this last table, I thought to share a set of other options that enthusiasts may find interesting.
Eventually, we may see data for the full range of cars, but for now this sampling is the most complete analysis that I’ve seen. If you have a 991.1 GTS, I hope this helps you understand more about your car.