Ram Truck is questioning Ford's claim that its 2015 F-450 holds the "best-in-class" tow rating for heavy-duty pickup trucks announced earlier this month.

Ford made the claim at a media event in July after unveiling an upgraded 2015 F-450 with the capability to tow 31,200 lbs., which would give it the highest towing capacity among heavy-duty pickups. The 2015 F-450 would surpass the towing capacity of the Ram 3500, which now sits at 30,000 lbs.

Ram says the Ram 3500 competes directly with Class 3 pickups such as the Ford F-350 and GMC Sierra 3500. The Ram 3500 can be purchased in a variety of configurations topping out at 14,000 lbs. GVWR.

"Ram disagrees," said Nick Cappa, Ram's communications manager. "Our best-in-class claim of 30,000 lbs. of towing capacity for the 2014 Ram 3500 stands firm in the 350/3500 segment."

Ram claims the F-450 should be considered a Class 4 medium-duty truck because of its heavier weight rating. Ford has said the truck — offered only as a crew cab 4x4 — just fits within Class 3, which tops out at 14,000 pounds, according to the U.S. Department of Transportation's Federal Highway Administration.

The battle for towing supremacy is heating up as the Detroit 3 begin to adopt the SAE J2807 towing test criteria for new models. Ram has adopted the standard for its 2015-MY heavy-duty pickup trucks, while Ford has elected to wait to roll out the standard with fully redesigned Super Duty models. The 2015 F-150 will be Ford's first truck to meet the standard.