Detroit rock heroes Bob Seger and Kid Rock on the same concert bill is about as rare as an Edsel.

Friends for more than a dozen years, Seger and Rock took a tour test-drive Friday at the sold-out Xcel Energy Center. It wasn’t a finely tuned machine — this two-night duo detour (they’re in Fargo on Saturday) while each is in the midst of his own headline tour — but it was a spirited, good time that proved that rock and roll never forgets, no matter what generation it belongs to.

In his headline set, Seger, 67, opened with what could be the theme for their future tour — “Detroit Made,” a John Hiatt tune detailing all the fine qualities of a Motor City ride.

After a 10-year hiatus to raise his two kids, Seger returned in 2006 with an album and tour, and he toured again in 2011, making noise that he might retire for good. But on Friday, it was obvious he’s been working on his night moves. He looked better this time — thinner, and those tobacco-stained teeth finally met white strips. He was more talkative (“Turn the Page” was written in Eau Claire, he said) and more energetic, strutting down a small runway, working the whole stage and even using live video for the first time. He’s not as athletic as 60-something Bruce Springsteen, Steven Tyler or Mick Jagger, but he was in strong voice and spirit.

Moreover, a hot new younger guitarist, Rob McNelley, was like a new sparkplug in the Silver Bullet Band. A Nashville session player who has toured with Delbert McClinton, he offered solos on “Travelin’ Man” and “Old Time Rock ’n’ Roll” that reinvigorated those oldies. Nice move, Seger.

To the delight of the 17,000 fans, Seger dusted off “Like a Rock,” which has been hibernating from his live set list for a good 20 years. The set was filled with classic-rock radio staples from the 1970s and ’80s — from the acoustic-guitar-driven “Against the Wind” to the smoldering “Mainstreet” (elevated by Alto Reed’s sax solo).

Seger’s songs are like rock ’n’ roll comfort food. His presence is comforting, too. Seger was like the famous old quarterback who shows up at the rally to give a reassuring shoutout; Rock was like the wild and crazy fifth-year senior who can fire up any crowd.

In his opening 75-minute set, the always wired Rock, 42, was part hip-hop Hank Williams Jr., part redneck John Mellencamp. Rock can be as self-absorbed as any big-name rapper, but he peppers his songs and his patter with enough humor (loved his take on dancing Justin Bieber style) to make even a PC person smirk. Between all the braggadocio and pyro, there was even some honest-to-goodness, Seger-inspired musicality, most notably “Picture,” an affecting country duet delivered with Minnesota’s own Shannon Curfman (she’s in his band).

Rock showed some rare humility when, near the end of his set, he said, “I want to thank Bob Seger for even letting me touch the same stage.”

Of course, a couple of hours later they shared the stage for a four-song encore. It was no surprise when Kid Rock joined Seger for "Night Moves" or when the Rock Hall of Famer sang parts of Rock's biggest hit, "All Summer Long." But who expected Seger to rap on Rock's "Forever"?

"That's MC Bob Seger on the mic," Rock roared at song's end.

Seger was sporting the biggest grin you ever did see.

Then they finished up with Seger's "Rock and Roll Never Forgets." The gray-haired veteran reached out his hand to shake his partner's but Rock just gave him a big ol' Motor City hug that suggested that this test-drive should lead to a full-on joint tour.