Thanks jmic. It got to 40 below on us last winter and wet material. I was Happy to be on the grader instead of a scraper for most of that job. Frost is brutal in a scraper.
Kinda figured a few might ask about the specs so here they are from cats website
MODEL
NET POWER - TRACTOR/SCRAPER
CAPACITY HEAPED
TRAVEL SPEED MAXIMUM
627G
246 kW (330 hp) / 178 kW (239 hp)17 m351.5 km/h246 kW (330 hp) / 178 kW (239 hp)22 yd332 mph
View Specifications
637G
345/373 kW (462/500 hp)26 m354.9 km/h345/373 kW (462/500 hp)34 yd334.1 mph
View Specifications

Here is the page I copied and pasted from
http://www.cat.com/cda/layout?m=37840&x=7&location=drop
The ones in the winter pictures are 627's and the summer ones are 637's. Hooking together like that is called push pull loading. We hook together and unhook without stopping, all four loaded and gone in about 45 seconds. We were cyceling every 5 minutes and dumping full speed in 8th gear. What a blast. Its some good fun if you have good partners to work with.