Saul Seward Armstrong (born July 28, 1962), known professionally as Shane Diesel, is an American pornographic actor and director.

Diesel moved from Las Vegas, Nevada to Los Angeles, California at age 22 in pursuit of a career in bodybuilding. In February 1992, at age 29, he began posing solo for several magazines. He had an opportunity to do porn at this time, but he refrained because his parents, he said, "were still alive, and it didn't seem right." In 2010, New Sensations created a dildo replica of Shane Diesel's penis.

A few years after the events of 9/11, changes in airline travel took effect after certain legislation, and Shane received a huge paycut from his airline job. He began his main venture into pornography in April 2002. Diesel says he was fortunate to start porn at age 39 because porn at a young age "can really screw you up." He picked the name "Shane" because he wanted a name that began with "S" (his first choice was Shawn), and he picked the name 'Diesel' after a porn worker told him that he resembles, in many physical aspects, Vin Diesel.

Diesel signed an exclusive performing contract with Digital Sin in 2005. He eventually became known for his role as Blackzilla in several series produced by Hush Hush Entertainment. In January 2008, looking to pursue a career in directing, he retired from the role.

In 2014, he said that he still holds his long-time airline job, where everyone knows that he is a pornstar.

He says that managing these two jobs (pornstar and airline work) is "a double life," as he transforms into another person named "Shane Diesel" on-screen.

In February 2008, Diesel signed an exclusive directing contract with Vengeance XXX, the ethnic line of New Sensations, to develop, star in, and direct films. His directorial debut for the company was the film She Only Takes Diesel.

Diesel and Ashlynn Brooke were jointly interviewed by AskMen in 2008 on how to audition for porn.

Diesel was married to Czech pornstar Jana Romančáková, alias Jessica Dee, who died on June 29, 2012 in a car crash in Port-of-Spain, Trinidad.

Despite the racial themes in his works, Diesel maintains that he dates "all types of women" in his personal life.

He says he judges "by charm, personality, and of course sexuality."

The racial themes, he says, are simply the result of consumer demand; it is what people want to see.

In 2014, Diesel revealed having a 29-year-old son who did not discover that his father did porn until he was 24.

This son asked Diesel "to hook him up" with some of the girls in porn, but Diesel refuses to have his son exposed to "the kind of knuckleheads I deal with."

Diesel lost his virginity at age 18 to a 30-year-old woman.

He says he has always favored older women.