In animated form, car show sputters

Everything is relative. One man's Starbucks is another man's car oil. By the clock, the premiere of the PBS cartoon adaptation of NPR's "Car Talk" is approximately 25 minutes and 10 seconds long, but for me it lasted an eternity. Click & Clack's highly-rated radio show may roll ahead like an old jalopy, fueled by Boston accents and self-referential yuks, but "Click & Clack's As the Wrench Turns" barely inches forward on four flat tires.

The idea behind the series, which begins with back-to-back episodes tonight at 8 on Channel 2, is to expand the "Car Talk" brand to TV, just as Ira Glass's radio show "This American Life" has taken visual form on Showtime. But Click & Clack brothers Tom and Ray Magliozzi and their producers have chosen the exact wrong TV style to usher their sensibilities to the screen. "Click & Clack's As the Wrench Turns" refashions the guys, their Good News Garage co-workers, and their radio and TV cohorts into cuddly 1970s Saturday-morning cartoon characters. Most contemporary animation for adults uses softly-drawn lines as a stealth vehicle for sharp satire, but this cartoon reduces the world of "Car Talk" to bland cutesiness.

Inauspiciously, the first episode is about the brothers' over-the-top attempt to raise money for a PBS pledge drive. They must raise $5 million or be "done for," as their producer, Beth Totenbag, puts it. This concept allows for lots of PBS plugging, including jokes about PBS coffee mugs and "Nova," in the guise of wit. But while "30 Rock" has managed to ridicule NBC while indirectly promoting it, "As the Wrench Turns" does not operate as smoothly. All the PBS-ness starts to irritate. Eventually, the brothers run for president, with plans to use federal matching funds to rescue the show. Alas, this chance for knowing political sarcasm devolves into an opportunity to show how stubborn and thick the brothers truly are.

While "As the Wrench Turns" has the Magliozzis' unmistakable voices going for it, the show is missing an important part of the radio show's formula: The callers. The Tappet Brothers, as Click & Clack are known, have built their names on their interactions with troubled car owners, as well as on their own twisted rapport with each other. Maybe a reality-garage series with real car owners would have been more engaging, more able to capture the interactive atmosphere of the radio show; maybe not. Hard as it may be to accept in this age of multiple-platforming, not every brand is expandable. There's much to be said for leaving us wanting more instead of less.

Matthew Gilbert can be reached at gilbert@globe.com. For more on TV, visit boston.com/ae/tv/blog.