Car dealer Brad Sowers is spending money to prepare for the coming wave of new electric models from General Motors Co. He is installing charging stations, upgrading service bays and retraining staff at his St. Louis-area dealership to handle the technology-packed vehicles. But when he considers how many plug-in Chevy Bolts he sold last year—nine, out of the nearly 4,000 Chevrolets sold at his Missouri dealerships—it gives him pause.

“The consumer in the middle of America just isn’t there yet,” when it comes to switching to electric vehicles, he said, citing the long distances many of his customers drive daily and a lack of charging infrastructure outside major cities.

As auto executives and investors buzz about the coming age of the electric car, many dealers say they are struggling to square that enthusiasm with the reality today on new-car sales lots, where last year battery-powered vehicles made up fewer than 2% of U.S. auto sales. Most consumers who come to showrooms aren’t shopping for electric cars, and with gasoline prices relatively low, even hybrid models can be a tough sell, dealers and industry analysts say.

Auto makers are moving aggressively to expand their electric-vehicle offerings with dozens of new models set to arrive in coming years. Some like GM are setting firm targets for when they plan to phase out gas-powered cars entirely.

Many dealers say that puts them in a delicate spot: They are trying to adjust, but unsure whether and how fast customers will actually make the switch. About 180 GM dealers, or roughly 20%, have decided to give up their Cadillac franchises rather than invest in costly upgrades that GM has required to sell electric cars.

A GM spokesman said the company expected some Cadillac dealers to opt out and is pleased that the roughly 700 remaining share its all-electric goals.

Past attempts by car companies to expand electric-car sales have largely flopped, saddling retailers with unsold inventory. Even now, some dealers say they are reluctant to stock electric models en masse.

“The biggest challenge is that dealers have a bit of ‘boy who cried wolf’ syndrome,” said Massachusetts dealer Chris Lemley.

Car companies have promised for years to make electric cars mainstream, but produced only low-volume, niche models, he said. He recalls Ford Motor Co. rolling out an all-electric Focus that sold poorly and stacked up on his lot. It was discontinued in 2018.

“So when we are told, ‘This time, we really mean it,’ it’s easy to be skeptical,” Mr. Lemley added.

Some shoppers also are unsure. Joe Daniel, an energy analyst at the Union of Concerned Scientists, said he was determined to buy an electric car, but eventually abandoned his effort after realizing there weren’t enough public charging stations near his apartment in Washington, D.C. Without a place to plug in, the purchase made little sense, he added.