Lucas considered covering duties as the sole cinematographer, but dropped the idea. Instead, he elected to shoot American Graffiti using two cinematographers (as he had done in THX 1138) and no formal director of photography. Two cameras were used simultaneously in scenes involving conversations between actors in different cars, which resulted in significant production time savings. After CinemaScope proved to be too expensive, Lucas decided that American Graffiti should have a documentary-like feel, and shot the film using Techniscope cameras. He believed that Techniscope, an inexpensive way of shooting on 35 mm film and utilizing only half of the film's frame, would give a perfect widescreen format resembling 16 mm. Adding to the documentary feel was Lucas's openness for the cast to improvise scenes. He also used goofs for the final cut, notably Charles Martin Smith's arriving on his scooter to meet Steve outside Mel's Drive-In. Jan D'Alquen and Ron Eveslage were hired as the cinematographers, but filming with Techniscope cameras brought lighting problems. As a result, Lucas commissioned help from friend Haskell Wexler, who was credited as the "visual consultant".
Despite unanimous praise at a January 1973 test screening attended by Universal executive Ned Tanen, the studio told Lucas they wanted to re-edit his original cut of American Graffiti. Producer Coppola sided with Lucas against Tanen and Universal, offering to "buy the film" from the studio and reimburse it for the $775,000 (equivalent to $4,437,291 in 2016) it had cost to make it. 20th Century Fox and Paramount Pictures made similar offers to the studio. Universal refused these offers and told Lucas they planned to have William Hornbeck re-edit the film.
When Coppola's The Godfather (1972) won the Academy Award for Best Picture in March 1973, Universal relented, and agreed to cut only three scenes (about four minutes) from Lucas' cutan encounter between Toad and a fast-talking car salesman, an argument between Steve and his former teacher Mr. Kroot at the sock hop, and an effort by Bob Falfa to serenade Laurie with "Some Enchanted Evening"but decided that the film was fit for release only as a television movie.
However, various studio employees who had seen the film began talking it up, and its reputation grew through word of mouth. The studio dropped the TV movie idea and began arranging for a limited release in selected theaters in Los Angeles and New York. Universal presidents Sidney Sheinberg and Lew Wasserman heard about the praise the film had been garnering in LA and New York, and the marketing department amped up its promotion strategy for it, investing an additional $500,000 (equivalent to $2,697,526 in 2016) in marketing and promotion. The film was released in the United States on August 11, 1973 to sleeper hit reception. The film had cost only $1.27 million (equivalent to $7,271,432 in 2016) to produce and market, but yielded worldwide box office gross revenues of more than $55 million (equivalent to $296,727,886 in 2016). It had only modest success outside the United States, but became a cult film in France.
Universal reissued Graffiti in 1978 and earned an additional $63 million (equivalent to $231,332,143 in 2016), which brought the total revenue for the two releases to $118 million (equivalent to $433,288,776 in 2016). The reissue included stereophonic sound, and the additional four minutes that the studio had removed from Lucas's original cut. All home video releases also included these scenes. Also, the date of John Milner's death was changed from June 1964 to December 1964 to fit the narrative structure of the upcoming sequel More American Graffiti. At the end of its theatrical run, American Graffiti had one of the greatest cost-to-profit ratios of a motion picture ever. Producer Francis Ford Coppola regretted having not financed the film himself. Lucas recalled, "He would have made $30 million (equivalent to $161,851,574 in 2016) on the deal. He never got over it and he still kicks himself." It was the 13th-highest-grossing film of all time in 1977, and, adjusted for inflation, is currently the 43rd highest. By the 1990s, American Graffiti had earned more than $200 million (equivalent to $366,632,705 in 2016) in box office gross and home video sales. In December 1997 Variety reported that the film had earned an additional $55.13 million in rental revenue (equivalent to $82,249,297 in 2016).
Universal Studios Home Entertainment first released the film on DVD in September 1998, and once more as a double feature with More American Graffiti (1979) in January 2004. Aside from the four minutes originally deleted from Lucas' original cut retained, the only major change in the DVD version is the main title sequence, particularly the sky background to Mel's Drive-In, which was redone by ILM. Universal released the film on Blu-ray on May 31, 2011.