[Putershark]

From what I have been advised,
Ring Free is nothing more than Chevron's "Techron" product in a different bottle. So you might want to save some cash and just pick it up at the Auto Parts store. I think this has also been discussed in the past, so you may want to punch the word Techron into the site search tool for more threads on that product

Here again, Startron is suppose to also remove carbon deposits without using the harsh solvents that Techron does. Along that same thinking, I do remember what Porsche was telling me years ago that Techron is a little hard on engine oil if used in large doses (3 bottles in a row with 3 tanks) since it causes all that carbon to break free and in time, make it into the crankcase. This is why we always recommended changing the oil after using 3 bottles of the "Clean Up" version of the product. Not something though (carbon) that I want flowing through my engine like little chunks of sand for a very long period of time.

I would assume that using both products might be a little overkill after a while, and your wallet just getting cleaned out faster than anything This is why I am just going to stick to my combo of Chevron Premium fuel (which already has a certain amount of Techron) and Startron alone and see how that works out