Try running 91? And maybe run some Seafoam and turn off the engine? (In hopes that it sits on the pistons and cleans them better)

Sea foam helped tremendously on my 2000 Prelude SH. Car ran much smoother and had better throttle response after.

While the video does show what I think is carbon removal, it's difficult for me to appreciate the differences, and some appears to just be the lighting.

Huge props to the author of the video, but I would like to see further controls on the camera he used. I think he should have sealed the spark plug hole from light when he had the camera down in the cylinder, and should have marked the cable from the camera so that he could insure it was inserted the same amount for before and after pictures. While I think I am seeing a cleaner ring around the outside of the pistons, it looks like it could also just be different lighting.

When I drove it cross country last year we ran 93 the whole way from san diego to CT and it loved it. But now since its a beater winter car 87 is all she gets. I just run amsoil fuel cleaner ever month and its pretty good so far. still gets 30 + mpg and starts up everyday.

:tup:
I think you should run higher octane because it will prevent knock, not for any other reason. Good luck :tiphat:

http://www.reactiongifs.com/r/2013/06/opinionated.gif

I don't think it's all lighting, I think a majority is actually carbon being cleaned. There's more definition in the piston heads

Similar experience here with a Honda Prelude, only last a couple a months. I think it does remove some surface carbon, but the thick crusted carbon on the piston top is what caused the knocking.

My mechanic showed me a piston with the crusted carbon. It would take some hard work to scrape off with a screw driver. There is no way that seafoam can remove that.

A better solution is to prevent the carbon buildup by using fuel treatment periodically.

Just my 2 cents.;)