Gas HEMI or Cummins diesel: how the two powertrains differ
The standard 6.4L HEMI V8 makes 375 horsepower and 429 lb-ft of torque and keeps the purchase price down. It also carries the higher payload: because the V8 weighs less than the diesel, gas 5500s are rated up to 12,370 lbs versus 11,530 lbs for diesel trucks. The trade-off is combined weight, with gas models capped at a 28,500-lb GCWR and 21,230 lbs of towing. The available 6.7L Cummins turbo diesel makes 360 horsepower and 800 lb-ft and raises the ceiling to a 37,500-lb GCWR in 4x2 form and 43,000 lbs with 4x4, good for up to 34,540 lbs of towing. Both engines now use the TorqueFlite HD 8-speed automatic; for 2026 the diesel drops the old Aisin 6-speed, which improves shift quality and PTO integration. Wrecker, hotshot, and heavy-trailer work justifies the diesel. Dump, service, and municipal bodies that stay under 28,500 lbs combined usually pencil out better with the HEMI.

