As if the long-running “Fast & Furious” franchise didn’t give us enough of muscular men and muscle cars, we now get a spin-off teaming Dwayne Johnson and Jason Statham as Luke Hobbs and Deckard Shaw, who first came to blows in 2015’s “Furious 7” but have since become reluctant partners when threats arise to global wellbeing. Heretofore the two have acted as part of the larger “Fast & Furious” ensemble, but now they take center stage in their own stand-alone unlikely-buddy action movie; but aware of the need to connect it to the franchise, the makers came up with the unwieldy title it’s saddled with (perhaps a wise idea, given how the recent “Dark Phoenix” bombed partially because it wasn’t associated clearly enough with the “X-Men” brand.)

The threat that Hobbs (Johnson), a straight-arrow US diplomatic security agent, and Shaw (Statham), a disgraced British military man turned mercenary—who are introduced in juxtaposed fight scenes extraneous to the larger plot—take on as a pair is one mounted by a shadowy but all-powerful outfit called Etion, based, it seems, in Ukraine (and housed, apparently, at an abandoned nuclear facility), and presided over by a mysterious disembodied boss who communicates through a digitally-altered voice via a massive computer system. (The voice ultimately identifies itself as an old foe of Hobbs’s.)

While he remains a behind-the-curtain Wizard of Oz type (at least until the sequel), however, his chief enforcer is front and center. He’s another rogue British ex-agent, Brixton Lorr (Idris Elba), whom Shaw thinks he killed, but was resurrected by Etion and turned into a sort of six-trillion-dollar superman, half human and half technologically-advanced cyborg. Brixton is immensely strong and virtually invulnerable, a Terminator imbued with belief in his boss’s malign plans for the world.

Those plans are depressingly familiar—they involve culling weak humans from the pack through use of a programmable virus nicknamed Snowflake, which would serve a function similar to that of the infinity stones in “The Avengers,” if only on a global scale. In any event, the movie opens with Lorr attempting, but failing, to steal the virus from a group of MI6 agents. He’s foiled by one of them, Hattie (Vanessa Kirby), who escapes after injecting the virus formula into her own bloodstream and thus becomes his new target—as well as a supposed traitor herself. She also happens to be Shaw’s estranged sister, who—as we’re shown in flashbacks—used to join in juvenile criminality with Deckard and their late brother Owen.

Hattie thus becomes the focus of our heroes’ mission too, and after a car chase in which they rescue her from Brixton’s clutches and a second extrication from a high-rise office building, they become a trio. Their goal is twofold: to save Hattie’s life by removing the virus from her, and the world’s population by defeating Brixton and Etion. The unsanctioned mission will take them to Madam M (Eiza González), a weapons supplier in Russia, and then the Etion complex in Ukraine, and finally to Hobbs’s family residence on Samoa, where he will after a long absence make up with his brother Jonah (Cliff Curtis) and, with his clan and their friends, face off against Brixton and his remaining minions.

As with all the “F&F” movies, Chris Morgan’s script for this one continually emphasizes the bonds of family; so we get Deckard reconnecting with Hattie and Luke with Jonah. There’s also a maternal element, with scenes emphasizing Shaw’s mom Queenie (Helen Mirren) in prison and the Hobbs matriarch Sefina (Lori Pelenise Tuisano) insisting that her boys bury the hatchet and work together. But that’s not all: there’s also the cutesy relationship between Hobbs and his daughter Sam (Eliana Sua), who’s never met her grandma and uncles.

None of this goes very deep, of course; “Hobbs and Shaw” is essentially a comic book in live-action form, and though there are the usual dull expository scenes, and plenty of opportunities for the mismatched pair to hurl supposedly clever (but actually lame) insults at one another, the emphasis is on the big set-pieces. These begin with hand-to-hand combat scenes to show off the brawn of both stars, which work their way up to the twin rescue sequences (the one featuring Shaw’s fast car being chased by Brixton’s shape-shifting motorcycle, the other with the good guys chasing Lorr and his men down the side of that gleaming high rise). All are well staged by Leitch and his team in the kinetic style he brought to the first John Wick movie and “Atomic Blonde,” though flash is really all they have to offer.

But even these seem puny beside the chase, complete with drones, big trucks and Brixton’s motorcycle, at the Etion command center—a sequence preceded by the requisite torture session perpetrated by Lorr on our two captive heroes. The movie could easily have ended there, but the makers apparently felt that they hadn’t satiated the audience’s demand for the kind of really over-the-top stuff the most recent “F&F” pictures have traded in, so we get the final confrontation on Samoa—in which the locals face off against Lorr’s army wearing traditional garb with no-tech weapons. This culminates in a hilariously ridiculous sequence in which Brixton’s helicopter is literally lassoed by Hobbs and held close to the ground by a convoy of linked trucks as they’re dragged along winding mountainous roads. After that pursuit closes with an explosive burst, there follows a long, brutal bout in which our heroes face off against superman Lorr and best him by—you guessed it—working together.

These final thirty minutes can be justified as paying tribute to Johnson’s Samoan heritage, but they might just constitute the most absurd half-hour in action-movie history—although, to be fair, it has plenty of competition. You might first note its complete dismissal of the most rudimentary realism when it begins at the onset of evening, then abruptly moves into bright, sunny daylight, and ends in a sudden monsoon. But what makes it truly risible is when our heroes explain to the defeated Brixton that his crusade is doomed because it’s based on technology rather than people. For that message to be conveyed in a movie that’s a factory-engineered machine in which the human characters are all wafer-thin is the ultimate irony.

Both Johnson and Statham do their beefy he-man routines with their customary efficiency, of course, and Kirby makes a spunky heroine who can hold her own with them. (She also has a superpower, in that the terribly bloody wounds she suffers to her face miraculously disappear by the next day—a common occurrence in such movies.) Elba is a fine actor, but he’s unable to do much with the sneering Brixton, having to repeatedly recite ponderous pronouncements about being the next stage of human evolution. (The idea of a bad guy that can’t be killed, moreover, might sound like a good idea in theory, but proves fairly boring in practice.)

In the supporting cast, Mirren gets a couple of scenes to do low comedy, and Eddie Marsan brings some panache to the part of a Russian scientist. Otherwise the pickings are rather slim, unless you find hilarious the extremely broad comic interruptions provided by a couple of “surprise” guest stars—Ryan Reynolds, doing his usual snarky, fast-talking routine as the CIA agent who drags Hobbs into the mission (Rob Delaney does a similar job on Shaw, but in a lower key), and Kevin Hart as a US air marshal desperate to get in on the action. His name is Dickley—just one of the many puerile jokes here about male physical equipment (you could probably start a drinking game in the frat house by counting the number of times “balls” occurs without any reference to sports).

Technically, of course, “Hobbs and Shaw” is a pricey proposition, shot efficiently by Jonathan Cela, but as is often the case with such CGI extravaganzas, the visual effects are often slightly off. Oddly enough, that seems rather appropriate for a movie that’s essentially a brainless, formulaic, derivative but extravagant live-action cartoon, and as such likely to appeal to fans of the most recent overblown “Fast & Furious” installments.