Here is some background. My car is a 2006 nissan 350z with the vq35de engine. It has around 90k miles on it and it has never used a fuel cleaner as far as I know.
ROYAL PURPLE MAX CLEAN

This is the first one I wanted to try... for no apparent reason...
I only use the piston as my comparison... because its easy to get to, and I'm lazy.
So here is one of my pistons before:
After:
Conclusion: I DON'T LIKE IT.... NOT ONE BIT. It looks worse than it did before.
ps. I'm going to be trying gumout later as well as the chevron techron
