The fact that I'm creating a topic of this nature may come to a surprise to many of you, but I feel it's necessary because I'm getting at least three different answers based on my own research.
1) Wikipedia: http://en.wikipedia....ilm#Super_16_mm
WP states the camera aperture is 12.52 by 7.41 mm (0.493 by 0.292 in). This gives us an aspect ratio of 1.6884:1 (1.69:1). Unfortunately, nothing is cited clearly in that article (shocker!). For an interesting twist, the entry also lists regular 16 mm as having a height of 7.49 mm (0.295 in). I thought Super 16 just extended the horizontal dimensions of the format, not also shrink it's vertical dimensions.
2a) Arri: http://www.arri.com/...16416_plus.html (click on the "Technical Details" tab)
2b) Panavision: http://www.panavisio...rmats-guide.pdf
I lumped these two together because they both cite the same specifications: 12.35 by 7.49 mm (0.486 by 0.295 in). This gives us less horizontal resolution than what's listed in WP's entry, but now matches the height of regular 16 mm. We now have an aspect ratio of 1.6475:1 (1.65:1).
3) Kodak: http://motion.kodak....INFOGRAPHIC.pdf
You'd think these guys would offer evidence corroborating with the camera makers, but they say it's 12.42 by 7.44 mm. Their Super 16 "Sell Sheet" (http://motion.kodak....oices/index.htm ; click the Super 16 mm tab) at least confirms that regular 16 mm is still 7.49 mm in height. Their Super 16 film dimensions calculate to an aspect ratio of 1.6694:1 (1.67:1) which is the closest match to the often touted 1.66:1, in my opinion.
So we're left with three different physical descriptions. Which one is correct? What does SMPTE, ANSI, and/or ISO state for the record? (I'm not a member of any so I'd appreciate it if those who were could chip in.)