Note that we are not planning to full time in the Rockies, and we will certainly spend some time on flat land, but I don't want to be climbing at 10mph up-hill and out of control downhill when we run into these steep grades. So, I guess we'll need a real jake brake too.
Our 6.6/6.7 LDT size diesel engines don't use the real jakebrake (engine brake). However Pacbrake has has a P-67 Load leash engine brake for the 6.7 Cummins if you want to spend some big bucks.
The Cummins uses the Holset variable geometry turbo (VGT) with a sliding nozzle as a exhaust brake. This includes a program with the auto tranny torque converter clutch which locks on down grades. Testing has show it has better exhaust braking power than the other two.
Ford and GM diesel uses the variable vane turbo (VVT) along with the TC clutch lock up program that acts as a exhaust brake. GM seems to have the better exhaust braking power between the two.
The new model one ton DRW trucks have GVWRs up to 14k lbs and more importantly 9700-9800 RAWR for carrying any 5th wheel trailer pin weight safely.
The 80 percent figure thrown around comes from a era when even our biggest engines were limited to 230-250 hp and 375-400 ft lbs torque. The new gen diesels run from 650-850 torque and 375+ hp. These truck will pull 100 percent of their rating safely. Their not your dads '90s/early '00s 235/250 hp diesel engines.
