Consumer Reports suggested Tuesday that General Motors may have overstated fuel economy of many more than the 60,000 large crossover vehicles that dealers are holding until window stickers are replaced.

The automaker notified dealers last week after discovering an inadvertent error which affected the fuel economy information on window labels of the 2016 model-year Acadia, Enclave and Traverse. The error caused the Environmental Protection Agency-estimated fuel economy on the label to be 1 to 2 m.p.g. more than it should have been. GM is stopping sale of the affected models until it can ship new and accurate labels.

General Motors didn’t directly address Consumer Reports’ contentions in a statement released later Tuesday:

“New emissions-related hardware in the 2016 Chevrolet Traverse, GMC Acadia and Buick Enclave, required new emissions testing,” GM’s statement said. “That data was not captured in calculations made for EPA fuel economy labels and caused 2016 model year fuel economy numbers to be overstated by 1-2 miles per gallon for these vehicles.”

The company also said its engineers discovered the error when they worked on the 2017 model year labels. The error was quickly reported to EPA, and “we continue to work with the EPA on this issue.”

GM is also contacting owners who already bought or leased the affected models to inform them of the issue.

But Jake Fisher, director of automotive testing for Consumer Reports, said the problem doesn’t end with the 2016 models.

For example, Fisher said the Environmental Protection Agency’s site fueleconomy.gov shows the combined city/highway fuel economy for the 2015 Acadia all-wheel drive at 19 m.p.g.— or two m.p.g. better than the revised numbers on the 2016 model.

Fisher said he and colleagues reviewed their own fuel economy results from tests they did of the Enclave and Traverse as far back as the 2007 model year and found that they achieved an average of 15 m.p.g. in combined city and highway driving on the Enclave and 16 on the Traverse. The EPA-certified number for that model year was 18 m.p.g. for both.

There have been no major changes in the three models through 2016 that would have added significant weight or otherwise caused an increase or decrease in fuel economy. The Acadia has been redesigned for the 2017 model year and is 740 pounds lighter than the 2016 model.

Fisher acknowledged that different tests can lead to different fuel economy results depending on the type of driving and terrain covered.

“But the vast majority of the overall fuel economy and the combined fuel economy and what the EPA finds are very close,” he said. “In this case the difference was more than 10%.”

All three models have been strong sellers. The new stickers should arrive this week, according to GM spokesman Tom Wilkinson.

The error prevented Glenn Buege from delivering about five cars sold to customers over the weekend at his Lansing GMC and Buick dealership and his Chevy dealership in Eaton Rapids.

“It’s kind of a ridiculous reason for not being able to deliver a car,” said Buege, president of the two dealerships. “It’s a problem because people want to pick them up when they buy them.”

Buege said he expects to get the new labels by Monday afternoon or Tuesday afternoon.

Terry Hanks, owner of Sundance Chevrolet in Grand Ledge, said the dealership had to give at least three customers rental cars while they wait for the new sticker to come in for the Traverse.

Despite not being able to move 20 Traverses off his lot, Hanks said the issue hasn’t big “a big deal.”

In late 2012, Consumer Reports tested the 2013 Ford Fusion hybrid and C-Max hybrid and found their combined mileage came in at 39 m.p.g. and 37 m.p.g., respectively, compared with 47 m.p.g. posted on the window sticker.

Over the next 18 months Ford reduced the reported fuel economy numbers on six models, including twice on a few models.

In the case of the GM crossovers, the company acted on its own and the discrepancy is smaller.

Contact Greg Gardner: (313) 222-8762 or ggardner@freepress.com. Follow him on Twitter @GregGardner12. Alexander Alusheff of the Lansing State Journal contributed to this report.