Another Chart And A Question

[J3Studio]

Below is a chart I built recently showing the relative lengths of all eight generations of the Riviera (click on the image for somewhat higher resolution). Of course we know that the early seventh-generation cars were the shortest and I've noted that the first, sixth, and eighth generations are really close in length.

 

The initial length data for 1976 was displayed incorrectly—I have updated this chart to avoid passing on bad information.

Edited February 27, 2020 by J3Studio (see edit history)

[Turbinator]

Most interesting gathering of data and charting. I have no answer to your question. 
I enjoyed reading your post.

Turbinator

[NC1968Riviera]

16 hours ago, J3Studio said:

Below is a chart I built recently

Cool chart, John. Too much time on your hands?

[Seafoam65]

Your info on the chart regarding the 75 and 76 models is bogus. An internet search reveals that

the 74 was indeed 226 inches long, but the 75 and 76 models were shortened to 223 inches, the same length

of the 73 Boat Tail Rivieras, not 218 inches as your chart shows.

[J3Studio]

9 hours ago, Seafoam65 said:

Your info on the chart regarding the 75 and 76 models is bogus. An internet search reveals that

the 74 was indeed 226 inches long, but the 75 and 76 models were shortened to 223 inches, the same length

of the 73 Boat Tail Rivieras, not 218 inches as your chart shows.

 

218.6 inches is what Buick themselves quoted for 1976 and what is in every reference I could find, including:

 

http://rivowners.org/features/Ev_Stats/dimensions.html

 

and Flory, Gunnell, et al. Are those all wrong for 1976? I guess it's possible … it's hard to see any significant difference between the 1975 and 1976 in photographs. My chart does show 223 inches for 1975.

 

I have made a note in the original post that the 1976 length data is in question.

Edited February 26, 2020 by J3Studio (see edit history)

[J3Studio]

2 hours ago, NC1968Riviera said:

Cool chart, John. Too much time on your hands?

 

Still working on the Riviera Project and still learning. And yes, my time is way oversubscribed …

[Hazdaz]

I think like Seafoam suggested that the data is not correct. 

 

Another option is that maybe, just maybe where the length is measured from is different.  For instance, maybe regulations changed and one year you included the length of the entire car, while the next year they didn't count the length of the little bumper add-ons.   Kind of like how pre-1972 power was rated as SAE "gross" horsepower (at the crank) vs the way it is rated now (net power).  The same engine would give vastly different numbers if it was using one metric or the other.

 

If you are looking to expand this chart, I would be curious to see how other dimensions changed throughout the various generations.   The width and height will be interesting to see, but also the wheelbase for older cars has dramatically changed over the years for all cars, so curious how that evolved in the Riv. 

[J3Studio]

On 2/25/2020 at 7:19 PM, Hazdaz said:

I think like Seafoam suggested that the data is not correct. 

 

Another option is that maybe, just maybe where the length is measured from is different.  For instance, maybe regulations changed and one year you included the length of the entire car, while the next year they didn't count the length of the little bumper add-ons.   Kind of like how pre-1972 power was rated as SAE "gross" horsepower (at the crank) vs the way it is rated now (net power).  The same engine would give vastly different numbers if it was using one metric or the other.

 

If you are looking to expand this chart, I would be curious to see how other dimensions changed throughout the various generations.   The width and height will be interesting to see, but also the wheelbase for older cars has dramatically changed over the years for all cars, so curious how that evolved in the Riv. 

 

Oh, I get it—but it's not like I didn't check and double-check (and I hate posting incorrect information). If the brochure is flat-out wrong (by that much) and no one ever caught it, than that's what it is. I do see typos in Riviera brochures, but they're usually by an inch or less—not almost six inches. Maybe I can find the SAE model submissions; one would hope they're right.

 

Your observation about the possibility of changes in measuring standards is worth exploring. If all the Buick lengths have the same kind of discontinuity for 1976, than that might be it. I'll give it a try. The cynic in me wonders if 1976 Buick might have been more in favor of a shorter quoted length than 1974 Buick. It certainly makes for an easier transition to the 1977 Riviera.

 

I'm happy that you find this chart interesting, and do intend to do others. I find that visualizations help me understand these cars.

 

 

Edited February 27, 2020 by J3Studio (see edit history)

[Rivdrivn]

Among other things, I’m a data analyst and biostatistician. So I love charts and graphs that are well done and I very much appreciate the effort here. These things convey a lot of information in a format that’s easy to digest and remember. This can impact real world decision-making, e,g, I built my extra 3-car garage to be 24’ x 36’ so, in a pinch, I could stuff four of my Rivieras in there if I had to.

[Barney Eaton]

Looking at the "standard catalog of Buick" 3rd edition,   it shows the overall length of the '75 and '76 Riviera at 218 inches

In their 1977 description of the Riviera they say "it received a total restyling.....and lost 5 inches of length and some 700 lbs."

They go on to list the overall length of the LeSabre and Riviera at 218 inches.    If the '77 lost 5 inches then the '75-76 should be 223

 

I would say that somehow bad info got released on the overall length of the '75-76 Riviera and it got copied to other publications.

[J3Studio]

On 2/27/2020 at 9:57 AM, Barney Eaton said:

Looking at the "standard catalog of Buick" 3rd edition,   it shows the overall length of the '75 and '76 Riviera at 218 inches

In their 1977 description of the Riviera they say "it received a total restyling.....and lost 5 inches of length and some 700 lbs."

They go on to list the overall length of the LeSabre and Riviera at 218 inches.    If the '77 lost 5 inches then the '75-76 should be 223

 

I would say that somehow bad info got released on the overall length of the '75-76 Riviera and it got copied to other publications.

 

Yep. It looks like 1976 should be 223 inches (I was always pretty sure 223 was right for 1975). I'm going to check a couple of things and revise the chart shortly. So much for "original sources" …

 

… that's another brochure "lie" to add to the 1965 deluxe saddle interior and the non-existent GS interior monogram in 1968 and 1969.

Edited February 29, 2020 by J3Studio (see edit history)

[Barney Eaton]

I have a pretty large collection of showroom literature from the '50's, '60's, '70's and '80's.

Because of the printing lead time and then getting them out to dealers to have when the new models came out, it was common

to find pictures and accessories that changed.    Often the photos are from preproduction vehicles.

One classic example is the 1955 Thunderbird that shows the swooping side trim on a T'bird that was the same design used on the

production Fairlane models. .... but not used on the production T'bird.

[J3Studio]

3 minutes ago, Barney Eaton said:

I have a pretty large collection of showroom literature from the '50's, '60's, '70's and '80's.

Because of the printing lead time and then getting them out to dealers to have when the new models came out, it was common

to find pictures and accessories that changed.    Often the photos are from preproduction vehicles.

One classic example is the 1955 Thunderbird that shows the swooping side trim on a T'bird that was the same design used on the

production Fairlane models. .... but not used on the production T'bird.

 

Agreed—and it happened well into the 1980s. Chevrolet printed four separate versions of the 1984 Corvette brochure (I have one of each). The early versions of the brochure include the "standard" 15-inch wheels that never shipped on any C4 Corvette.

[steelman]

2 hours ago, J3Studio said:

 

Agreed—and it happened well into the 1980s. Chevrolet printed four separate versions of the 1984 Corvette brochure (I have one of each). The early versions of the brochure include the "standard" 15-inch wheels that never shipped on any C4 Corvette.

Because 15" wheels would not clear the redesigned larger brakes of the C4.

[J3Studio]

Chart updated—thanks to @Seafoam65 for pointing out the questionable data for the 1976 model year, and thanks to everyone else on this thread for their context, suggestions, and support.

Edited February 28, 2020 by J3Studio (see edit history)