"Greased Lightning" now at area theaters, is pleasant, unassuming and somewhat maddeningly lackluster. A sketchy chronicle of the career of Wendell Scott, a Virginian who broke the color line in stock-car racing, becoming the first black driver to win a NASCAR championship, the film seems to grow out of a conception so carefully lightweight and inoffensive that it borders on the ephemeral.

The perfunctory script, which creates the impression that dramatic scenes were considered so much filler between the racing sequences, is credited to a quarter of writers, including Melvin Van Peebles, who began as the director and was then replaced by Michael Schultz, who steered "Cooley High" and "Car Wash" to commercial success. There's no evidence that Scott's personality or achievement aroused strong feelings and deep dramatic instincts in anyone involved. On the contrary, it's rather too easy to jump to the probably mistaken conclusion that the subject himself is more virtuous than colorful.

The audience seems to anticipate a livelier brand of satisfaction than the filmmakers are prepared to deliver. For example, Richard Pryor and Pam Grier would appear to suggest romantic comedy possibilities that are barely recognised in "Lightning," where they're co-starred for the first time as Scott and his wife Mary but kept under wraps. It's possible for stars to overdo it when they decide to impersonate ordinary, salt-of-the-earth folks. Pryor and Grier have never seemed quite so restrained; unfortunately, all this admirable restraint begins to feel like a waste of natural resources.

Beau Bridges, cast in what one presumes to be a trumped-up, token-white role as a redneck hotrodder who becomes Scott's buddy and mechanic, and Cleavon Little as an ebullient crony of the hero enjoy the luxury of creating eccentric, uninhibited characterizations. They don't have to be as respectable as Pryor, who seems reluctant to take the role of Scott beyond conventional sincerity and libility, perhaps because he's more concerned with giving no offense than having a good time.

Bridges has become remarkably good at portraying reckless sporting types. His performance in "The Other Side of the Mountain" was indispensable to that picture's sentimental appeal. The character he plays in "Lightning" is expendable, but his performance is fresh and amusing. The movie might have been more amusing if Pryor and Gier had been released from their nice role-model obligations and encouraged to make Wendell and Mary Scott as distinctive and idiosyncratic as the supporting characters. They could be a funnier, rowdier married couple without ceasing to function as a model of marital devotion and family stability.

Like Junior Johnson, Scott evidently prepped for his career by running moonshine, but the filmmakers don't do much with this special form of on-the-job training and its social and folk-heroic implications. It's simply the pretext for slapstick car chases, one of the more exhausted forms of hilarity on the contemporary screen. The film also lacks a mounting sense of drama about Scott's pioneering role in this sport and a climatic race staged with enough skill and excitement to send everyone home on a high, happy note of vicarious triumph.

To be sure, the movie ends with Scott's winning race, and it's even complicated by showing him coming off a crippling injury and driving the last few laps with three lugs missing on one wheel. Nevertheless, these details are not exploited in a way that would lift the sequence to new heights of suspense. We ought to see this competition exacting a harsher physical toll on the hero, and there ought to be a payoff shot of that wobbly wheel after the race has been won.

As it is, not even the neck-and-neck last lap is shot in a style calculated to intensify suspense. The director appears to be stuck with rather drab shots from inside the racers showing one car creeping ahead and then falling back. The effect is not exactly thrilling, but the audience is obviously eager to be thrilled and more than willing to do its imaginative share. "Greased Lightning" never generates enoughmomentum to meet the audience half-way.