Rush slip on spark plugs

[FLIPBEL]

I installed rush slip on 1.75 on my 2009 egc about 200 miles ago and I wanted to show the difference in the color of the plugs. Well I am happy to find out that there is no difference in the color. I added before and after pics.

 

[Hoople]

Flip,
Were you expecting to see the plugs go even leaner in color?. Trust me, you won't. I have made Dramatic changes in my A/F ratio and the plugs go unchanged due to the E10 fuels today. It drove me crazy until I learned what was going on.
I have ran 12.5:1 air fuel ratios and the plugs looked near white.

 

[FLIPBEL]

After all the posts I had read about Rush 1.75 I was more + then - in regards to the color. I just wanted to make sure.

 

[Hoople]

After all the posts I had read about Rush 1.75 I was more + then - in regards to the color. I just wanted to make sure.

It can't be checked by plug color. Everything else being equal, E10 alone is .3 A/F ratio leaner than non-alky. Meaning if you A/F ratio was adjusted and measured at say 13.8 with Non-alky fuel, just filling your tank with E10 will result in your A/F ratio now being 14.1

You need to pump more fuel in with the same amount of air to have the same A/F ratio at the pipe.