In a small mixing bowl or measuring cup, whisk together red wine vinegar, vegetable oil, kosher salt, black pepper and sugar until sugar and salt dissolves. This step is important so that you don't get grainy bits of undissolved sugar or salt in your coleslaw.
Pour over coleslaw mix. Toss well. I find that using forks works best for coleslaw.
Cover and refrigerate for 1-24 hours. If you remember to toss it every few hours, great, if not, it will be fine.
Drain excess liquid before serving. The cabbage will lose its water, so you will have more liquid than you started with. This is normal.
If you've tried this recipe, come back and let us know how it was!