This is a guide to try and fix some stuttering for people playing Outriders. It's not a guarantee, your results may vary, but hopefully this will help some others out there.
Stuttering? Try This!
If you play on Steam, and you are experiencing stuttering, open Steam while you are playing, (Shift+Tab) and "view all friends" and click your name and go offline.
This will remove the stuttering and or lag, at least for me. I came across this solution on a discussion comment and I am in turn posting this guide here so others can see it and hopefully play lag free.
Why does this fix it? I don't know, I am not a developer, I just know it fixed it for me.