What "cleaners" does Shell Premium have that its midgrade and/or regular don't have? Don't all grades of Shell meet Top Tier standards?In my Turbo Sonata, I use Premium Shell, not for the octane, but for the cleaners in it. Of course, my Sonata gets great mpg compared to your (and my former) Genesis, so the extra cost of (Top Tier) premium does not matter to me.
Hahahahahahah, But still though do we know for sure like any test results?Top tier is top tier. The only thing different between grades of fuel from any top tier provider is octane, which is the measurement of how much pressure a fuel can withstand before pre-detonating. In an engine that doesn't directly adjust to a higher pressure for a higher octane gas, premium fuel provides ZERO additional benefit. Use what the manual recommends: regular unleaded. If you want to pay for premium, use regular and send me the extra money ;-)