i found a place close to home that sells 100octane ethanol free gas.

how do you think it would run in my 8 as i don't race it?

 

In a word "lousy". More is not better. The engine is designed to run on a certain octane. Using a fuel with too much octane would be slightly similar to retarding the timing and would not be great for performance or fuel economy.

 

i was thinking more that the ethanol-free would be better, regardless of octane

 

Has anyone ever mixed premium and regular gas per fill-up? For instance the 60/40 ratio.

 

As mentioned earlier in a different thread- don't post in multiple threads with the same question. It is considered spamming and you could get banned. Just wait for someone to respond to your question. This isn't McDonald's where service is 5 minutes or less... if you want that service, you need to learn to use the search feature.

For your question, you can use the 60/40 ratio. But, it's recommended to just use full premium gas. It's what the renesis was designed for.

 

Mid grade gas is a 50/50 mix of premium and low grade at most stations. Just ask them sometime. They only have 2 tanks for 3 blends.