Wow... this thread turned into far more than what I expected! Tire wars!

In an effort to get back to my original post, here are the results of the first part of my testing.

The woman who in my opinion is the world's best stoker was kind-hearted and amused enough to join me on a 2½ mile ride to the nearest "hill" in our area. It's a freeway overpass with light traffic. The wind was calm and the temperature was about 45°.



We started at a point that was about 12 feet above the surrounding area. My wife is standing there in the picture above. From there we coasted along the street (it's is parallel to the street in the foreground) until we stopped. We were very careful not to push off when we started, and I was very careful not to extend our coasting by oscillating the handlebars as we slowed. I was also careful to ride along the same part of the street each time we coasted.

Here are the results with our inexpensive 700x35c tires pumped up to 90psi:

#1 518.8 ft
#2 516.6 ft
#3 499.2 ft
#4 499.2 ft
#5 483.8 ft

Average: 503.5 ft
Standard Deviation: 12.9 ft (just 2.6% of the average)
Note: Every time my speedometer showed a maximum of 11 mph.

I'll post more results once I mount the 700x28c Gatorskins, hopefully tomorrow.

In the meantime y'all can argue some more about slicks vs. treads, high vs. low pressure and so on.

Edit: I just noticed that the results were sorted in descending order by my phone, where I noted them. That is not the actual order. For example, the 499.2 ft measurements were really #1 and #3.