Is V your lucky number? If you’re a hard-core fan of “The Fast and the Furious” — the high-octane street-racing movie that opened in 2001 and has ignited not one, not two, not three, but four sequels — fortune is indeed smiling: When “Fast Five” arrives in theaters Friday, it will have most of the original cast in tow, a parking lot’s worth of automobiles, and a mix of velocity and mass that will defy the laws of physics.

Whether the franchise itself is out of gas, of course, remains to be seen. As movie franchises go, V times has not been a charm.

Achieving three sequels is a milestone, or it used to be, at any rate. This year, when one in five films in major release will be a sequel to something — and here it starts to get confusing — five of those movies will be fourth installments, including “Mission: Impossible — Ghost Protocol” and “Pirates of the Caribbean: On Stranger Tides.” While one should never say never — Sylvester Stallone could be wearing Depends before Rocky finally hangs up his gloves — many of the more successful franchises in film have hit the wall at IV. “Die Hard,” “The Exorcist,” “Jaws,” “Rambo.” Not to mention “Anaconda,” “Airport,” “Species,” “Bring It On” and “Bloodsport.” Considering the level at which these productions were operating when they made their exits, four wasn’t just enough. It was too much.

But if you think IV is scary, consider this: There are another five movies looming out there, awaiting nationwide distribution, that will be V’s: “Fast Five,” of course, and also “Final Destination 5,” “Puss in Boots” (aka “Shrek V”); “X-Men: First Class” and “Winnie the Pooh.” Just to cover the bases, “The Muppets” and “Rise of the Planet of the Apes” technically will be seventh installments in their respective canons, and one, “Harry Potter and the Deathly Hallows Part 2” (you may now genuflect), is No. 8.

“Five” is special, though. Who can forget “Death Wish V: The Face of Death”? Or “Seed of Chucky” (which followed “Bride of Chucky” and Chuckys 1, 2, and 3)? On the other hand, who can remember “Saw V,” “Halloween 5: The Revenge of Michael Myers” or “A Nightmare on Elm Street: The Dream Child”? In the realm of horror/slasher extravaganzas, plot lines and continuity become obscured by blood, and with the exception perhaps of “Henry V,” movies with a V seem to dwell in a remote kind of obscurity (including “V for Vendetta”). The series, however, continue lurching forward.

But when one ponders the concept of sequels, and in what order films actually rank, there has sometimes been a bit of confusion, never less than when George Lucas started numbering his “Star Wars” films from the middle of the series (IV, V and VI followed by I, II and III). If you go by Lucas, the V in his series was a pretty good movie. If you go by chronology, not so much.

But many of the movies that provided so much inspiration to Lucas and Steven Spielberg in their “Star Wars” and “Indiana Jones” projects — the movie serials of ’40s — went well beyond five installments, as did a number of other franchises that weren’t quite serials: There were six “Thin Man” movies starting in 1934, although by No. 5 (1944’s “The Thin Man Goes Home”) they’d started to lose some of their joie d’vivre. There were 14 Boston Blackie films made mostly in the ’40s, not counting the silents that preceded them. James Bond has hit the screen 22 times (No. 5: “You Only Live Twice”). The Bowery Boys, in their various incarnations, made 48 pictures. Number five? Who even wants to know?

“Fast Five” (unseen at press time) doesn’t seem to be shifting gears from what has made it a $489 million franchise (including “2 Fast 2 Furious” of 2003, “The Fast and the Furious: Tokyo Drift” of 2006 and “Fast & Furious” of 2009). The star of the original, Paul Walker, returned for “2 Fast 2 Furious” (without Vin Diesel), teaming up with Tyrese Gibson. But Walker sat out for “Tokyo Drift,” in which Lucas Black starred instead, and in which Diesel made a cameo at the end. The third and fourth sequels, “Fast & Furious” and “Fast Five,” both feature Diesel, Walker and Jordana Brewster reprising their roles from the first film. Michelle Rodriguez, who was in “The Fast and the Furious” and “Fast & Furious,” is not in “Fast Five,” but who’s kidding whom? The cars are back, and that’s what counts.

And it’s a general rule of movie franchises that shtick, not people, keep them racking up the numbers and rolling to the bank. Quick: Who’s the star of “Transformers”? Does anyone seriously think that a “Harry Potter 9,” with or without Daniel Radcliffe, wouldn’t conjure up box-office receipts in the hundreds of millions? Or that “Fast and the Furious: Revenge of the Prius” wouldn’t do very well indeed on a Friday night in April? There have been six James Bonds, any number of Batmen, and if you wear a hockey mask, no one knows who you are. But audiences know what they’re going to get. And like knowing there’s always a bathroom at McDonald’s, it’s very reassuring.