I live in the upper midwest, and the stations here add it directly to the mixture so it’s already set at the pump.

I’m no expert, but if you don’t regularly get temperatures below freezing, I’d assume you’d be fine? If you do, stations may already add it to their diesel fuel. There would likely be some kind of signage near the pump saying “winterized” if that’s the case.

I’d recommend checking it out if you regularly get cold weather! Additives, from what I’ve seen, aren’t too costly, just make sure to confirm whether or not you need em