Several other automakers were understanding of that rationale and are assessing whether it makes sense to follow suit.
"We think it's interesting and a pretty significant development for the industry," Mark LaNeve, head of U.S. sales for Ford Motor Co., told reporters during a call to discuss March sales. "Their comment that there's a lot of volatility in month-to-month sales, I believe there is some validity to that. So we're going to assess it and take a look."
Hyundai Motor America also believes "there is a lot of merit to a quarterly sales reporting cadence" and is discussing its options, said Jim Trainor, a company spokesman.
American Honda, which has long tried to spotlight the role of competitors' incentive programs and fleet sales in skewing monthly sales comparisons, echoed GM's concerns last week. But it said it plans to continue monthly reporting for now.
"I think we can acknowledge that the monthly reporting process can be frustrating when the news media reports simple ups and downs and declares winners/losers without analysis of the levers being pulled to drive those results," said a company spokeswoman.
Fiat Chrysler declined to comment. The company told Reuters that it would continue a monthly reporting schedule for now. (FCA changed its internal sales reporting practices in 2016 and revised some results after a federal investigation.)
Jaguar Land Rover, Subaru and Toyota Motor North America were among other automakers that said they have no plans to change their sales reporting for now.
Brian Brockman, a spokesman for Nissan North America, said the company is taking a wait-and-see approach.
GM said it will continue providing monthly sales data to the U.S. Federal Reserve, other government agencies and industry associations across the globe, but those data won't be made public. The decision doesn't change the way dealers report monthly sales to the automaker.
Even if others follow GM, it could take years for the entire industry to move to quarterly reporting, much as it did with the shift to monthly reporting from 10-day intervals. The former Chrysler Corp. eliminated 10-day reports in 1991; GM didn't do so until 1994.
"What happened was they decided to go monthly, and everybody did it," said Michelle Krebs, executive analyst with Autotrader. "That would make me believe everybody is going to follow suit and follow GM's lead."
Switching to quarterly sales reporting, Krebs cautioned, could lead to "less transparency" and "leave an information gap" for the industry, which could lead to more error-prone speculation and extrapolation — particularly if some automakers follow GM but others do not.
GM argues that it is not being less transparent, as it will still break out each month's results with the quarterly report. The report will include total deliveries, brand and nameplate sales, fleet mix and inventory.
But GM has been steadily scaling back the amount of data it provides publicly. Five years ago, it decided to stop reporting North American production. A year later, it discontinued its monthly sales call. Ford and others still provide those reports.
The shift reflects GM's broader effort since its 2009 bankruptcy to focus Wall Street investors' attention on innovation, services and financial discipline as key drivers of its business rather than the manufacture and sale of traditional vehicles.
Before reaching the decision, the company said, it analyzed nearly three years of stock trading data on sales days and researched how other industries and companies report sales. GM benchmarked companies such as Amazon, Apple, AutoNation, John Deere, Penske, Walmart and Whirlpool — none of which report sales monthly. Tesla also reports its sales quarterly instead of monthly.
GM's Canadian operations will continue to issue monthly sales results, spokesman Jim Cain said.
GM will drop monthly reports in China, its largest market, and Brazil, but GM China's joint ventures will continue to report wholesale volumes to government and industry associations. GM's operations in Brazil and Mexico will also continue to report sales to their respective associations.
GM's sales reporting for 2018 will be July 3, Oct. 2 and Jan. 3. — already scheduled sales reporting days for the auto industry.