2012 deleted Cummins and never used an additive, and have no issues.
210k miles currently. I’m nervous of changing my routine but can be convinced too if worth it.
Religiously Oil and filter every 5k, fuel filter every 10k.
Do I need to start using an additive?
Im no mechanic, I just know a couple good ones, one of them has been using additives for many years in his older duramax and highly recommends it. He says diesel is dirty enough, I think it helps keep the injectors cleaner. If you start now, I wonder if you'll blow some good smoke at the first dose? Might be worth a try.