I own a 2009 hyundai santa fe , it has 100k miles on it, i got the car since it was new, never used fuel additives, is it more dangerous than useful to start using additives now?
[Updated with Issue]: Rough idle issues, the engine stopped working in low speed twice in a few months, replaced the canister, fuel pump , cleaned maf and throttle body last week, it seems a bit better but still not smooth when idle, btw waiting for a replacement purge valve to arrive and ill replace it too
The only fuel additive I would ever use is Techron to keep the injectors clean.
There is no harm.
If you don’t have any issues, I would not use fuel additives.
Ignore my comment, since your initial post did not include the issues you were experiencing.
My bad, after reading about the issues im having, would you say its ok to try additives?
You never said which engine you have. Try a new PCV valve. How old is yours?
https://www.autozone.com/emission-control-and-exhaust/pcv-valve/hyundai/santa-fe/2009
Its a 2.7L v6