Well
A little knowledge is dangerous without curiosity. You're correct that the "octane" in of itself has minimal impact, but the additives found in higher octane gas do. Additionally, your EB motor is more efficient with premium, meaning less fuel used to do the same work. Less fuel means less byproduct such as carbon: although this is minimal. Also, the additives are not as efficient since they don't wash over the valve but some do make it.
How does Top Tier figure into this. I was under the impression that all grades got the additives.
Typically, the "additives found" are the same additives as their lower-octane counterparts, but at slightly higher concentrations.
I'm aware of the implications of octane on timing and efficiency, and how direct injection works. I've owned high-mileage Ford DI engines. But, thanks for helping out those of us with "a little knowledge" but "without curiosity", as you say.
Top Tier is just a quality assurance. Since gas has become so expensive there have been a few less than honest retailers. I guess it's a way of saying you're comparing apples to apples.
Sorry if it came across as insulting. I'm a bit defensive of the petroleum industry and get upset by all the wrong PR out there. I guess I assumed you read a single article on it to reach your conclusion, which shows I can also be ignorant. Even "Consumer Reports" wrote a piece saying premium did nothing. There are a lot of variables on this issue.
Ah, it's all good... I have the same frustrations and have to tell myself at times not to make assumptions as well. I probably should have realized that I might be "poking the bear" so to speak for making such a general statement about the subject anyway.
