If you’re shopping for a car, your first stop may be your smartphone.

As consumers grow increasingly comfortable buying smaller items such as clothes and concert tickets from their mobile devices, some are also using their smartphones and tablets for big-ticket purchases like cars.

“There’s this huge upheaval in terms of mobile usage and mobile behavior,” said Jeff Birkeland, vice president of product management for High Gear Media, which publishes the Car Connection site and app. “People are looking to not only research cars, but actually take action and connect to a dealer and do some business on mobile.”

Online companies are putting the entire car shopping experience on a mobile device, replacing the lengthy weekend trudge between dealerships with an afternoon on the couch with an iPad. The shift to mobile, tech companies and car salespeople agree, has armed consumers with more information and resources to prepare for what is for most of us a sizable and emotional purchase. Shoppers can research their new and used car purchases before going to the dealer, and with some mobile apps, even buy a used car.

Rodney Bonachita of Daly City, Calif., did much of his car shopping on his smartphone while he prepared last year to buy a 2009 Mazda. By the time he showed up at the dealership, he said, he was ready to write a check.

“Going [into dealerships] armed with information — I wouldn’t do it any other way,” he said.

With growing interest in car research apps, mobile devices are expected to become a go-to resource for 87 percent of car consumers, according to a 2012 study from Briabe, a mobile advertising company that surveyed more than 1,600 people planning to purchase a car within 12 months.

Car buyers using mobile apps can look for their next purchase between running errands or while making dinner, and on the weekend, they can use a tablet and not be chained to a desk. And shoppers are bringing these apps to the dealership, keeping their smartphones and tablets handy to show salespeople competing offers or lower suggested prices.

“They’ll be sitting there on their iPhones and iPads and checking, ‘What’s my car worth?’ ” said Richard Flores, sales manager at Courtesy Chevrolet in San Jose. “They have way more information than they ever had before.”

Still, plenty of consumers still want the dealership experience. Lorenzo Torres of San Jose said car shopping from an app is “lazy.”

“I don’t have to go online all the time for things I really want,” he wrote in a Facebook comment to the San Jose newspaper.

Dealers argue that the strong emotions tied up in buying a car — a purchase that families depend on to get safely to work and school — have as much influence on the buyer’s decision as any app.

“In most cases, it’s still an emotional car buying experience,” Flores said. “When you drive the car and feel the steering wheel (in your hands) — all that stuff affects you.”