Clint Eastwood gives his farewell performance in “Gran Torino,” and he has a lot of fun with the kind of tough, stand-alone character that has made him a box office favorite.

It’s no coincidence that this contemporary drama bears many of the plot points of “The Shootist,” a Western that was John Wayne’s final movie. Don Siegel directed “The Shootist” and was Eastwood’s mentor and favorite director. Both movies feature tough guys determined to go out with their boots on and with teenage boys who worship them.

Eastwood plays Walt Kowalski, a retired Detroit auto worker who has just lost his wife. He’s a sour old cuss who can’t abide changing times, minorities and just about everything else, including his own family. He lives on a diet of Pabst Blue Ribbons, cigarettes and beef jerky. He even scorns the priest who urges him to go to confession.

Walt’s world is really rocked when a Hmong family moves in next door. The Hmong are mountain people of Southeast Asia, and they really inflame Walt’s racist tendencies. Things get worse when the teenage son tries to steal Walt’s prize possession, a beautifully maintained 1972 Ford Gran Torino. The reluctant thief is named Thao, and he’s played capably by Bee Vang. Thao’s really a studious boy who loves gardening, but neighborhood gangbangers force him into the deed.

When the gang returns to enlist Thao, a fight breaks out and spills into Walt’s yard. The crusty geezer faces them down with an M1 Garand he brought back from the Korean War, which sets up the inevitable smackdown.

Meanwhile, Thao’s sister breaks down Walt’s resistance to his exotic neighbors despite the racial epithets he applies to her people. It’s kind of like the relationship with Hilary Swank in Eastwood’s “Million Dollar Baby.” Ahney Her plays the sister, and she gives a warm and charming performance as the undeterred ice breaker. Walt soon becomes her friend and Thao’s mentor, discovering that they have more substance than his own grandchildren.

Eastwood, also the movie’s director, and his screenwriters deal with a lot of issues. Among them are aging, bigotry, urban decline and matters of faith. Most important, the movie deals with the possibility of redemption at any age. Walt finally comes to terms with his demons, and it takes the Hmong family to get him there. The movie has some flat notes, but it’s ultimately an affirming take on a dependable theme — the man of action defending the meek. Typically, Eastwood the director stamps it with his own, idiosyncratic signature.

As for Eastwood’s last bow as an actor, it’s a pleasure to watch. He’s truly a lion in winter, growling at all the things that rankle him like a dyspeptic king of the jungle. Think of Dirty Harry when he’s old and cantankerous and doesn’t have anyone to make his day anymore. Eastwood isn’t making a somber, self-congratulatory exit. He’s going out making fun of himself in a near over-the-top condensation of all of his previous characters.