UPDATED: 8/814 3:24 pm ET - correction
Editor's note: An earlier version of this story misstated when General Motors started subtracting the weight of some items on its pickups before calculating their maximum payloads. The company started doing that on its 2014 light-duty full-sized pickups. And it started subtracting items on its 2015 heavy duty pickups.
DETROIT -- How hard is it to weigh a pickup?
If the revelations from Ford Motor Co. and General Motors over the past week are any indication, it is difficult indeed.
At issue is how Ford and GM calculate the maximum payload for many profitable pickups -- and the companies' changing stories on their methods.
To come up with the figures, the two automakers acknowledge, they delete the weight of some heavy parts, such as the spare tire or rear bumper, from the base curb weights of many of their pickups.
The practice allows the companies to claim a maximum payload capacity that is higher than the rating for the pickup's base model -- one with no added or deleted factory options.
With the practice, some pickup owners could conclude they can carry heavier loads than they should.
"It's gamesmanship, with manufacturers trying to be the king of the hill," said Mitchell Dale, a Ford dealer in metropolitan Houston. "Quite frankly, it could drive a concern about confidence when they play games like this."
Pickup rivals Ram, Toyota and Nissan rely on standard base curb weights to establish their payload capacities, without subtractions.
In the cutthroat full-sized pickup segment, a higher payload rating can provide a marketing advantage. Heavy-duty pickups accounted for about a quarter of the 1.1 million full-sized pickups sold in the United States through July of this year, industry sources say. With average transaction prices above $50,000, huge amounts of revenue are on the line.
On Monday, July 28, Automotive News reported on a pickup marketing dispute between Ford and Chrysler Group's Ram.
The story revealed that Ford removes some standard items from its pickups to give them a maximum payload that is higher than a base model's payload. At the time, GM said it didn't follow the practice.
But later, GM said it excluded items on its 2014 light-duty pickups. And it excluded items in 2015 heavy-duty lines.
The company says it will broaden the practice for the 2015 model year to its light-duty full-sized pickups.
The GM spokesman said the automaker adopted the practice "because we saw what the competition was using."
He said: "It was done to keep comparisons apples-to-apples when we launched the new trucks." The competitor was Ford, the spokesman said.
Ford began for the 2011 model year deleting the weight of items such as spare tires from its heavy-duty pickups' curb weights to set "maximum" payloads, a Ford spokesman said.
For much of the past two weeks, Ford has said it used the practice to set maximum payloads across its top-selling F-series pickup lineup. However, on Thursday, July 31, Ford said it deletes the weight of items such as the spare tire, jack, radio and center console to set the payloads only on its Super Duty pickups: the F-250, F-350 and F-450.
For the F-150, Ford now says, it has always used the base curb weight.
Dale, president of McRee Ford in Dickinson, Texas, said tussles among pickup makers over bragging rights can cause consumers to question manufacturer claims.
A consumer's expectation "is that a truck does what is advertised," Dale said.
"When we're starting to remove items from the vehicle, it would be my expectation that all manufacturers do their testing with production line vehicles similar to what a customer would drive," he said.
"We're so internally focused on having the bragging rights of whatever segment we're talking about that it appears that there are some questionable practices being done."
GM dealer Tommy Brasher, owner of Brasher Motor Co. in Weimar, Texas, is less concerned.
"I don't think it makes any difference to the customers," he said. Automakers "go to a lot of trouble to do that, and it doesn't mean anything to most people. It's bragging rights."
For consumers, the difference between a payload rating based on standard curb weight and one based on a weight with standard items removed can be confusing.
For example, Ford advises dealers to warn customers that they could disqualify their warranty coverage if they exceed a truck's gross vehicle weight rating.
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.
But Ford spokesman Mike 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."
Pickuptrucks.com, a Web site for enthusiasts, posted stories about the payload controversies last week.
As they did with Automotive News stories, online readers expressed frustration and anger at Ford and later GM for removing items from a base pickup to calculate the payload capacity.
But Mark Williams, editor of pickuptrucks. com, said he doubts customers will switch brands over the practice.
"The general sense I get from our readers is that they want to know as much about the process that manufacturers use as possible. But a couple hundred pounds here or there isn't going to make much difference to them."