I have a few to share:

Spectrum 2-8-0
per June 1998 MR
"45 free-rolling freight cars on straight level track"
drawbar pull 3 ounces

USRA 4-8-2 light
per Nov 1999
"30 cars on straight level track"
drawbar pull 2.2 ounces

USRA light 2-10-2
per August 2006
"52 free-rolling freight cars on straight, level track"
drawbar pull 3.7 ounces

USRA light 2-8-2
per February 2016
"30 free-rolling 40-foot box-cars on straight, level track"
drawbar pull 2.72 ounces

Need to dig up more, but figured that was a good start.

--Joe