system
Given the following post, respond as if you're commenting on Reddit:
human
[Back to the Future] What would happen if I put the DeLorian on a roller bench, ran it up to 88 MPH on the speedometer and then turned the time circuits on?
gpt
Nothing.

It's not the speedometer or the wheels that triggers the time travel, otherwise when Marty was stuck in 1885 they could have rigged up a gear system to spin the wheels to 88MPH.

The time machine itself needs to be traveling at 88MPH relative to its location in spacetime to break free of the time steam and travel through time.