After seeing the recurring questions about the ride height of the Model S and given that there is no quantitative answer yet, I decided to set out to determine an estimation based on what we have seen so far.
The way I measured ride height was by measuring distances in photos from Tesla's gallery. I needed a point of reference -- something that I could determine the actual size of so that I could determine the scale of the object and estimate the size of other objects at the same depth in the image. For that, I decided to use the wheel's lug pattern. It's a five-bolt pattern of which there are several different sizes. Specs are listed here: http://www.tirerack.com/wheels/tech/techpage.jsp?techid=92. The question was which one is it? Some of those lug patterns are much more common than others. I can't say I guessed correctly for sure, but the value I chose was 5x100 (or 5x4.0 in inches). My reasoning was that:
It made the wheels come out to nearly exactly 20" in diameter which several sites have sited as the wheel size.
It is the smallest of the five lug bolt patterns, so if anything my estimations would be too small, not too large.
The pictures I used to measure from were http://www.teslamotors.com/models/gallery/6307 and http://www.teslamotors.com/models/gallery/5082. I first measured using the silver / grey car that is at an angle and only measured near / around the front passenger wheel to avoid messy perspective calculations that could be wrong depending on the setup of the camera that took the shot. Then I measured the picture of the maroon car (most likely the prototype many of us have seen in person). I measured each car independently, establishing scale for each on separately.
Problems with this method:
I made several estimations / guesses, so numbers are likely off -- especially if I misjudged the bolt pattern.
These are all alpha or prototype cars and ride height may change.
Sub-pixel measurements were made and that will induce a margin of error. Where I included digits after the decimal point, they're not worth anything.
The images from the links above -- download the original from the link above the image.
Inkscape to load the images and take measurements at a sub-pixel level (I just drew a line while recording how many pixels long the line was)
A calculator to determine scale and to scale up measurements from their pixel values to inches
Feel free to remeasure and contradict my results -- I don't claim to be an expert. Also, before you respond saying that this method is wildly inaccurate, you're right -- it is. It's only meant to give us a better idea of the clearance than we had before.
11.25 pixels = 1 inch
5.56 pixels = 1 inch
220 pixels / 19.6 inches
111 pixels / 20 inches
In front of front wheel
Couldn't see well enough
30 pixels / 5.4 inches
Behind front wheel
53 pixels / 4.7 inches
25.4 pixels / 4.5 inches
Base of door near hinge
80 pixels / 7 inches
39 pixels / 7 inches
End of door near midpoint between wheels
45 pixels / 8 inches