Is anyone using E85 to raise their octane level mixed with pump gas? The highest octane pump gas I can get in SD is 91 and I need at least 93 for my new TT chip. I have a file created in Excel that uses the "goal seek" function to calculate what my blend needs to be based on a desired octane outcome. So if I am blending into 91 I just punch that in and the formula spits out my % ratio of 91 to E85. The same works for 87 octane pump gas. Its quick and easy, and best of all accurate. I know there are other alternatives like race gas and the like, but blending with E85 is much more practical in my situation.