Editor's note: An earlier version of this story said incorrectly that Ford Motor Co. removes parts across all F-series models in setting maximum payload ratings. Ford, in a reversal, said today it only removes components on its heavy-duty trucks to establish payload ratings.
DETROIT -- General Motors says it deletes heavy items such as the rear bumper from certain pickups when it weighs them in order to boost the vehicles’ maximum payload ratings.
GM says it adopted the practice for the 2014 model year in response to competitive pressures as it launched redesigned full-sized pickups.
The practice is similar to one adopted by Ford Motor Co. about four years ago to show a maximum payload that is larger than would be possible if the automaker used the standard base curb weight of a pickup.
Ford said earlier it adopted the practice across its entire F-series lineup. Ford said today, however, it uses the base curb weight and does not remove parts on light-duty pickups when measuring payload capacity.
It's the latest in a series of revelations from Ford and GM about the lengths they go to achieve the highest possible payload ratings on some of their most profitable vehicles.
Chrysler Group’s Ram brand uses only an unmodified base curb weight on the Ram pickup, as does Toyota Motor Corp. to set the payload of its Tundra pickup, spokesmen for those two pickup makers said.
In a July 28 Automotive News story about a feud between Ford and Ram over towing claims, a GM spokesman said the automaker does not delete any items from its pickups when it sets their maximum payload capacities.
The spokesman, Tom Wilkinson, said Wednesday that the claim was made in error.
Maximum payload capacities are used, in part, to separate pickups into classes. The classes are based on the vehicle’s gross vehicle weight rating, which is equal to the pickup’s base curb weight plus its maximum payload.
If a pickup’s weight goes up, then its listed maximum payload capacity must be reduced if it is to remain at the same gross vehicle weight rating. And, if a pickup’s weight goes down, then its maximum payload figure can climb by an equal amount and keep the same gross vehicle weight rating.
In an e-mail Wednesday to Automotive News, Wilkinson said GM establishes a minimum curb weight -- and thus a higher maximum payload capacity -- on some of its heavy-duty vehicles by deleting the weight of the rear bumper and switching out heavier standard steel wheels for optional lighter alloy wheels.
“You can delete the rear bumper, which some business customers do so they can install a custom bumper or other equipment on the back of the truck,” Wilkinson said.
He also said the maximum payload claims for the 2015 Chevrolet Silverado 1500 and GMC Sierra 1500 are based on a minimum curb weight that deletes the rear bumper and the spare tire.
A Ford spokesman said last week that Ford bases its maximum payload claim on the weight of the base F-series model after various items are deleted, not on the base curb weight of the F-series pickup.
For example, Ford shaved 154 pounds from the weight of the F-450, Ford spokesman Mike Levine said, by removing items that have the possibility of being deleted from a vehicle order.
Among the items removed were the spare tire, tire jack, radio and center console.
It began using the practice for the 2011 model year, Levine said.
Ford advises dealers to warn customers that they could disqualify their warranty coverage if they exceed a truck’s gross vehicle weight rating.
However, on the F-450, if a customer loaded a base vehicle to Ford’s advertised maximum payload capacity, the vehicle would exceed its Class 3 gross vehicle weight rating by 61 pounds.
Levine said Ford’s practice gives “customers, particularly commercial and fleet, the flexibility and information they need to maximize payload and stay within” the gross vehicle weight rating.
He said Ford lists for customers and dealers the exact weight of specific items that can be added or deleted from an order.
He said Ford prints “the net payload capacity of the specific vehicle (based on vehicle content) on the tire and loading label -- so the customer knows exactly how much net payload capacity they have.”
Levine said Ford customers “should also weigh their truck on a scale if they believe they are getting close to [the pickup’s gross vehicle weight rating], so they can make sure they do not go over.”