We tether each TTC rig to a 37,335-pound cement mixer that dwarfs the TTC machines and we have ’em attempt to pull the mixer as far as they can from a dead stop. Uphill. Yep, you read that right, uphill. We give ’em a short run on flat ground to gather some momentum and then our nasty dirt slope climbs 13 feet in altitude over its 150-foot length at a maximum angle of 16 degrees.