Originally Posted By: Hemi426
Not every fill-up. Just once in a while when I'm forced to get gas at an unfamiliar or discount brand station. It doesn't raise octane just improves the quality of gas.
How, exactly, does it raise the "quality" of the gas?
Honestly, I wouldn't bother with fuel additives unless I'm attempting to correct a specific problem (e.g. cleaning fuel injectors) that the product could address.
If one is concerned with fuel quality, it's probably better and cheaper in the long-run to primarily buy fuels from brand-name, "top tier" retailers (e.g. Chevron, Shell, 76, etc.) as opposed to the no-name brands, but all fuels sold in the US must meet federal (and in some cases, state) requirements for quality and additive levels.