20 Things You Didn't Know About The Terminator
16. The Endoskeleton’s Smoke Was Cigarette Smoke
The budget on the film was tight, and because of this, many corners were cut in order to get the shots. One of these cut corners occurs at the end of the film.
As the endoskeleton is chasing Connor at the end, missing half of its body, the smoke that emanates from its body as it's being crushed by the hydraulic press is actually cigarette smoke from the crew.
Cameron knew how to cut corners, having got his career started working with Roger Corman on small budget B-movies, so when presented with logistical challenges on The Terminator, he knew how to quickly solve them.
A similar corner was cut when Kyle and Sarah exit the tunnel after spending the night together, as the fog that covers the area was actually bug spray.