Originally Posted by Something_Awesome

There are a lot of people saying their 4Runners have some form of "improvement" by running 91 or better. A lot of people. And it's on many different platforms (not just here). maybe 35/65 split. If 35% of people are saying Premium improves performance, that's a strong minority. What's more is they provide technical explanations as to why this is. I always thought there was no affect.

I will investigate and use premium for the next two months and see what happens.

My suspicion though is that if anyone is seeing an improvement, it is likely more to do with the premium gas in your area having lower ethanol content. Just a guess. In Los Angeles, it appears that all grades using only 10% ethanol. I think we may switch to 15%. I wonder if 91 would stay at 10% though. I can't imagine these turbo'd, high performance cars loving more ethanol. If that happens, then 91 would be the move for me.