Gianni, this subject is sometimes like asking "what's the best oil to use in my car". It's a very subjective topic. However, to add my opinion, I use Startron at every fill up (diesel formula) and also RingFree as they are different products for different purposes. I use Startron in ALL my gas engines, big and small, when the fuel won't be readily used up since the gas doesn't stay "good" as long as it used to. Meaning, I don't use it my car since the gas gets used up so quickly. Although, it certainly wouldn't hurt to use it, either. For what it's worth, I have NEVER had a fuel issue related to gas going bad in ANY engine (numerous boats/engines, snow blower, weedwhacker, chainsaw, etc). Probably going on something like 10 or 12 years of using Startron. I used the Red Stabil before ethanol came on the scene, also with good results. But the red stuff doesn't address ethanol issues - you'd need the marine formula (360?) for that.