Lilley's Landing has ethanol-free in 87 octane. Based on many statements from Don Weed in the BBC Merc forums, I am hesitant to burn premium in my Merc ProXS. Below is a statement from Don that I saved as a reminder to myself. I believe that Don tends to error on the side of caution but when one has an outboard approaching 16K in value, I guess so do I. However, I'm interested in others perspective on this.
p.s. I've never tried to buy gas at Lilley's. Is it available at the street or dock?
Higher octane fuels burn SLOWER and COOLER. When utilized in an engine not DESIGNED for high-octane, this results in an INCOMPLETE BURN of fuel (and essentially, a richer operating condition- which contributes to carbon buildup). Also, because the fuel burns SLOWER and COOLER, the BTU output is LOWER, and the power produced per unit of fuel is actually LOWER. This means "less performance".