DETROIT -- In the flap over how General Motors and Ford Motor Co. calculate the maximum payload ratings of their pickups, GM blinked.
GM said on Friday that it no longer will omit the weight of some parts to boost the maximum payload ratings of their pickups.
Automotive News reported last month that GM and Ford exclude items from some of their pickups, such as the rear bumper or center console, to calculate maximum payload. The resulting figures are higher than would be possible if the automakers used a pickup's standard base curb weight.
That revelation drew criticism that the automakers were resorting to gamesmanship to one-up each other for bragging rights and marketing claims.
Ford said it excluded items to calculate payloads on just its Super Duty pickups: the F-250, F-350 and F-450. GM excluded items on its light-duty pickups starting in the 2014 model year. It excluded items in heavy-duty lines starting in the 2015 model year.
"As this story unfolded, we took a look at how the whole industry does this, and almost everybody uses base curb weight," GM spokesman Tom Wilkinson said. "We thought the best thing to do was line up with the rest of the industry to make those comparisons as easy as possible for consumers."
For the 2015 Chevrolet Colorado and Silverado 1500 and the GMC Canyon and Sierra 1500, which go into production in the fourth quarter, GM will use "maximum payloads based on base curb weights" in its advertising, catalogs and media materials.
GM also will update already-published specifications for its 2015 heavy-duty pickups to show payload ratings based on their base curb weights. The trucks were launched in January.
GM's reversal was first reported by Yahoo Autos.
Ford has said that it deletes the weight of items such as the spare tire, jack, radio and center console to set the payloads on its Super Duty pickups.
After GM's reversal, Ford said on Friday afternoon that it will retain the subtraction method to calculate payloads.
"We have made no changes to the way we determine maximum payload ratings for Ford F-series Super Duty," a Ford spokesman said.
Pickup rivals Ram, Toyota and Nissan rely on standard base curb weights to establish their payload capacities, without subtractions, the automakers have said.
Wilkinson emphasized that automakers' published maximum-payload ratings are for comparison purposes only. Pickup owners should refer to the tire and load information label on the door frame, which gives a vehicle-specific rating based on the pickup's options, GM said.
Maximum payload is the weight of all that a pickup carries, including passengers and cargo. When automakers subtract items from a vehicle's curb weight, that allows them to state a higher maximum payload.
Larry P. Vellequette contributed to this report.