How to determine uniqueness

[EttevroC]

Nice job... I looked over your figures and they look ok to me, but as I stated earlier, I am not a mathematician and was using the same Extrapolation calcs you used from the book. It seems logical...

However, I do have a mathematician in the family... one who teaches Calculus, Trig, Advanced Algebra, and an interesting little course called Probability and Statistics. I will try to sit down with her in the near future as our schedules permit and get her to help me with it.

JAG

If your relative is able to put into layman terms, please do share it with us.

 

[ProEMTPFF]

Cool, I'll check eBay out. Thanks!

Just bought one through 2005 @ Books a Million for 12.99. They had one in stock. Also, they offer it on thier web site.

 

[Achilles]

12 cars is a low number and it is realistically possible to have a one of a kind depending on all the option compinations available. For instance, we have a '95 Aqua coupe that was a special order from the previous owners. I haven't checked the #'s, but it could possibly be a "one of a kind" or close to it. If you consider such things as Spare Tire Delete, EMT Tires, Dual Roof Panels, etc., it seems very conceivable to have "The only one made". How's that for uniqueness?

 

[EttevroC]

12 cars is a low number and it is realistically possible to have a one of a kind depending on all the option compinations available. For instance, we have a '95 Aqua coupe that was a special order from the previous owners. I haven't checked the #'s, but it could possibly be a "one of a kind" or close to it. If you consider such things as Spare Tire Delete, EMT Tires, Dual Roof Panels, etc., it seems very conceivable to have "The only one made". How's that for uniqueness?

I think that would qualify, congratz!

 

[Vettelt193]

One MARJOR issue that no one has thought of is the convertible / coupe ratios. The ratio of manual to auto in coupes is higher than manual to auto in convertibles...

Meaning, there is a smaller percentage of 6-speed convertibles than there are coupes. As a matter of fact, it is kind of hard to find 6-speed convertibles, especially in the rare colors... (not white, black, or red)

 

[MyOtherCar]

One MARJOR issue that no one has thought of is the convertible / coupe ratios. The ratio of manual to auto in coupes is higher than manual to auto in convertibles...

Meaning, there is a smaller percentage of 6-speed convertibles than there are coupes. As a matter of fact, it is kind of hard to find 6-speed convertibles, especially in the rare colors... (not white, black, or red)

Yep, you are correct, it is impossible to determine how many of any option were split between the convertibles and the coupes. Take the 6-speed, all one knows for sure is that all 502 ZR1's came so equipped. But one has to take a stand somewhere and extrapolation provides the best means available for "us" to do so. I'm fortunate in that my Vette is yellow, so I start right off with a 3.3% ratio. BTW, I did find out that there are some ZR1 convertibles out there contrary to what GM says about all of them being coupes. There were some pictures of them posted, I think I remember two of them, a red one and a white one. So, I guess generalization is the key to the uniqueness of our vehicles.

Also BTW, how did you determine that the ratio of manuals/automatics was more or less in convertibles than in coupes???

 

[Ruby Fan]

I believe XLR's extrapolation was not correct. Here's why: If you say that 20% of all corvettes were painted white, and 60% of all corvettes had red interiors, the extrapolation example would say that of the 100% of white corvettes, 60% had red interiors. This is incorrect, because ANY percentage of red interiors could have applied to all the white corvette. All white corvettes could have been produced with red interiors, or maybe only 10%. The balance of red interiors percentage would apply to all corvettes painted any color other than white. So the extrap. can be taken then wrong way. The only true way to know is to get the data from GM. I thought they offered some sort of pay service for this on an individual basis.

 

[MyOtherCar]

Before anyone gets "wrapped around the axle" with these attempts at identifying the uniqueness of your Vette, please note the following:

EXTRAPOLATE: 1. to infer values of a variable in an unobserved interval from values within an already observed interval; 2. to project, extend, or expand known data or experience into an area not known or experienced so as to arrive at a usually conjectural knowledge of the unknown area.

 

[Vettelt193]

not to mention the fact that not all interiors were available with all exterior colors... meaning, you wouldn't have a green car with a red interior.... but white goes good with red, so a higher percentage of red will be attached to white, a higher rate of saddle interior would go with green....

 

[ZumZum]

Ouch

Ouch! My calculator just flashed a SES code!

 

[EttevroC]

One MARJOR issue that no one has thought of is the convertible / coupe ratios. The ratio of manual to auto in coupes is higher than manual to auto in convertibles...

Meaning, there is a smaller percentage of 6-speed convertibles than there are coupes. As a matter of fact, it is kind of hard to find 6-speed convertibles, especially in the rare colors... (not white, black, or red)

I agree with you full heartedly, most Convertibles would have been built with Automatics.

Not to bust on us Convertible owners, but I would suspect that Converts would have been more likely purchased as a pleasure car versus performance car, so I figured that my ride was somewhat a rare find.

 

[EttevroC]

I believe XLR's extrapolation was not correct. Here's why: If you say that 20% of all corvettes were painted white, and 60% of all corvettes had red interiors, the extrapolation example would say that of the 100% of white corvettes, 60% had red interiors. This is incorrect, because ANY percentage of red interiors could have applied to all the white corvette. All white corvettes could have been produced with red interiors, or maybe only 10%. The balance of red interiors percentage would apply to all corvettes painted any color other than white. So the extrap. can be taken then wrong way. The only true way to know is to get the data from GM. I thought they offered some sort of pay service for this on an individual basis.

If you can find out about that pay service please post it, I would like to know about it too. Heck, I've paid maybe to much for all my Vette's accessories, what's a little more going to hurt. :L

 

[Achilles]

It seems to me the correct way to determine the approximete number of white Vettes with red interior is to extrapulate the highest percentage first between white and red. Rather than assume that 60% of all cars built had red interior, leaving only red interior available for the remaining 20% of white cars. I would think that of all the exterior color choices, 60% of each color had a red interior. Unless it conflicted with the exterior color. Making it butt ugly! So, I believe the best way to approach this is to assume that 60% of the white cars built, may have had red interiors, 60% of black cars had red interiors, 60% of red cars...etc. Again, as I think everyone will agree, these estimates are just that...Estimations.

 

[XLR8]

E S T I M A T E S

I never claimed that I was on the money with the estimates I provided... in fact, I repeatedly mentioned this was all estimates based on extrapolation as explained in the reference book "The Corvette Black Book".

Extrapolation is defined in the book as "to project known data or experience into an area not known or experienced so as to arrive at a conjectural knowledge of the unknown area." It further states "Said another way, it means using what you know to guess what you don't."

Notice the key words here are project, conjecture, unknown, guess. That's all I could do with the data with my limited expertise (or more accurately lack of - HAHAHAHA).

Antonick further states in the book that generally, auto companies do not tabulate all the combinations sold, because "the number of combinations possible becomes enormous".

Maybe someone with more experience rating Corvettes for uniqueness could address the questions that have so far been raised. Especially the consideration that some interiors would not be chosen with some exteriors. This had occured to me, but I was going for a ballpark figure and had no "known" info to base a percentage on. The breakdowns in the book did not go that far.

Hope I helped, but if I didn't, I at least got everybody talking!

JAG

 

[Achilles]

Well said!

 

[EttevroC]

I never claimed that I was on the money with the estimates I provided... in fact, I repeatedly mentioned this was all estimates based on extrapolation as explained in the reference book "The Corvette Black Book".

Extrapolation is defined in the book as "to project known data or experience into an area not known or experienced so as to arrive at a conjectural knowledge of the unknown area." It further states "Said another way, it means using what you know to guess what you don't."

Notice the key words here are project, conjecture, unknown, guess. That's all I could do with the data with my limited expertise (or more accurately lack of - HAHAHAHA).

Antonick further states in the book that generally, auto companies do not tabulate all the combinations sold, because "the number of combinations possible becomes enormous".

Maybe someone with more experience rating Corvettes for uniqueness could address the questions that have so far been raised. Especially the consideration that some interiors would not be chosen with some exteriors. This had occured to me, but I was going for a ballpark figure and had no "known" info to base a percentage on. The breakdowns in the book did not go that far.

Hope I helped, but if I didn't, I at least got everybody talking!

JAG

I for one think you were very helpful, I knew what the precentages were but had no idea how to even start to extrapolate the estimate. Thanks bigtime!

 

[chadwick88]

Z51 perf.handling option

Now I am hooked, I just started investigating how unique my 88' with a z51 performance handling package maybe, and I have a question. How come in 1988 the z51 option cost is listed at $1,295.00, but every year after through 03' the cost was around $350 dollars??? heck even the years before 88' (87' through 85') the cost was only around $500 bucks...is there something special in 1988 that was offered in the z51 option that no other year has??? just curious...

 

[EttevroC]

Now I am hooked, I just started investigating how unique my 88' with a z51 performance handling package maybe, and I have a question. How come in 1988 the z51 option cost is listed at $1,295.00, but every year after through 03' the cost was around $350 dollars??? heck even the years before 88' (87' through 85') the cost was only around $500 bucks...is there something special in 1988 that was offered in the z51 option that no other year has??? just curious...

According to "Cor-Vette Specs" the only big difference between the 1987 and 1988 is that the convertibles front bracing that was added to the Z51 and X52 Vettes in 1988, and that the 17" wheels were optional. Both of these features were made standard on future Vettes. Other than that, it doesn't go out of its way to differentiate the 1988 Z51 cars.

 

[XLR8]

Well said!

Thanks! And thanks also for your contribution to the discussion.
BTW - A belated welcome to the

Enjoy!

JAG

 

[XLR8]

I for one think you were very helpful, I knew what the precentages were but had no idea how to even start to extrapolate the estimate. Thanks bigtime!

You're most welcome! Hope you can find more info on your baby soon.
BTW - That is one fine looking Corvette too. My first Corvette was a Torch Red C4 with black interior and a black top and I loved it! I hated to let her go but I had to after I bought my C5.

Enjoy and good luck!
JAG