Surface Water. COCKREHAM ISLAND BUY-OUT FEASIBILITY STUDY. The Cockreham Island Flood Hazard Reduction Buy-Out Study: Cockreham Island is located between the Towns of Lyman and Hamilton, in Skagit County, Washington, and is adjacent to the Skagit River.
And we certainly see a decrease in NOx without a significant increase in HC or CO. So, in some instances, buying a slightly higher octane fuel can both increase performance and help pass a failed emissions test. Generally, yes, spending money on higher octane than your owner's manual recommends is a waste of money. But sometimes ethanol tilts the scales. Of the 6 vehicles I've owned, 2 benefited from slightly higher octane-the other 4 suffered.
While it's true that pure ethanol has a higher octane number, (reason ethanol is ingredient used most often in octane enhancing gas additive products), E10 gas does not have an octane higher than conventional gasoline.(Choose grade of fuel at pump for octane you prefer). When E10 gas phase-separates (high octane ethanol drops to the bottom of the tank with water), the upper tank layer octane typically drops 2.5 points. 2  E.G. 87 octane gas purchased now becomes sub-octane 84.5 gasoline.