The German Tank Problem

[blackeneth]

During the World War II, the Allies used statistics to get very good estimates of German tank production. The Germans put sequential serial numbers on their tanks -- some of those tanks would be captured in battle, and allied intelligence would record the serial numbers found. Given the number of tanks captured, and the maximum serial number observed, one can get a very good estimate of how many were produced. See The German Tank Problem for more information.

I realized last night that the registry being collected by Rob could be used to estimate the number of Blackwings that GM is producing. We have numbers for 2022 -- during which GM produced 1,763 CT5-V Blackwings. After that, GM hasn't released information, with rumors and whispers that it's about 1,000 units a year.

Yet, Rob has been collecting the codes inscribed on the steering wheels, which GM numbers sequentially. For example, my 2025 CT5-V Blackwing (which I will take delivery on Thursday) is 86-0223, meaning it was the 223rd CT5-V Blackwing produced for the 2025 model year. This is all of the information we need.

Rob, if you could report by model (CT4-V Blackwing, CT5-V Blackwing) and model year, the 1) number of cars in the registry, and 2) the maximum serial number. Like the following:

Model Year	Number of entries	Maximum serial number
2022
2023
2024
2025

Then "we" can calculate the estimated production numbers for each model and year. I say "we" because, while I can certainly calculate it for you, it's actually trivial to calculate. Let k = the number of cars in the registry, and m = the maximum serial number. Then the estimate number of blackwings produced, N, is:

N = m + m/k -1

For example, say for CT5-V Blackwing, for 2025, you have 6 registries in the database and the maximum serial number is 669. Then the estimated production number would be N = 669 + 669/6 -1 = 779.5; round down to 779.

 

[quikag]

I haven't had enough coffee to fully decipher your post, but I believe the 86 in your 86-0223 means it's the 223rd SIX-SPEED CT5-V Blackwing. 81 is the 10-speed automatic.

Pretty sure that messes up your formula a little bit.

 

[668LT4]

I realized last night that the registry being collected by Rob could be used to estimate the number of Blackwings that GM is producing. We have numbers for 2022 -- during which GM produced 1,763 CT5-V Blackwings. After that, GM hasn't released information, with rumors and whispers that it's about 1,000 units a year.

86-0223, meaning it was the 223rd CT5-V Blackwing produced for the 2025 model year. This is all of the information we need.

The 1000 units per year "whisper" seems highly inaccurate. As quickag posted above, there an auto and possibly a manual for every number. I saw VINs on Cadillac's website for 2024s that ran into the 900s, so maybe 1600-1800 total +/- if manuals are a bit less than half of autos.

There is also no guarantee that the cars come off the line in sequential numbers, and for the same reason above, your car is more closer to the 446th +/- car produced than the 223rd.

 

[1Evil55]

I haven't had enough coffee to fully decipher your post, but I believe the 86 in your 86-0223 means it's the 223rd SIX-SPEED CT5-V Blackwing. 81 is the 10-speed automatic.

Pretty sure that messes up your formula a little bit.

+1
My 2022 is 81-0205. There is also an 86-0205.

 

[CaddyTrack]

 

[blackeneth]

+1
My 2022 is 81-0205. There is also an 86-0205.

The calculation can be done separately for the 81- and 86- series. Now, that means the maximum serial number needs to be determined separately for 81- and 86- series.

 

[TenTonTony]

For 2024 5BWs, the highest serial number vehicle still available in Cadillac inventory is 86-0942 for 6MT (@Sewell Dallas, I test drove this one!) and 81-1057 for A10.
There might have been a few higher serial units already sold, but I'd imagine it's not more than the next round hundred for each.

 

[minn19]

I thought this thread was going about the weight of the new M5 and the latest MB AMGs………….

 

[rdollie]

I thought this thread was going about the weight of the new M5 and the latest MB AMGs………….

Ditto

 

[FLYARMY]

Maybe this why BMW and Mercedes just use random VIN numbers. To throw off the American spies ! (Just kidding.)

 

[668LT4]

For 2024 5BWs, the highest serial number vehicle still available in Cadillac inventory is 86-0942 for 6MT (@Sewell Dallas, I test drove this one!) and 81-1057 for A10.
There might have been a few higher serial units already sold, but I'd imagine it's not more than the next round hundred for each.

Exactly what I was saying. So it is fair to assume 2000+ 2024s were produced. Double the "whispers and rumors". Which also makes sense that they did not decrease production compared to 2022. And Cadillac had a very strong 2024. No way they only made 1000 CT5-V Blackwings.

 

[BimmerFan]

Are we sure that they start the numbers over every model year?

Asking for a friend.

 

[Yalferd]

i thought it was about 1500 of each 4 and 5 per year. Not sure why this would be important to me