[rverdlm]

All that info on trailer brakes is very interesting, but the limiting factor is the 4 patches of rubber that meet the road. No matter how good the trailer brakes are (and IMHO regular trailer brakes are almost worthless) you're still trying to stop 18,000 pounds with 4 little patches of rubber. Your 6 to 8000 pound truck will have 4 or 6 or in my case 10 bigger patches of rubber.