Lets do the math, assuming that a blender pump has E10 and E15 as the two options and that there is 1/3 gallon in the hoses. If you pumped only 2 gallons of E10 after someone else just pumped E15 from that pump you would get: (.3 x 15) + (1.7 x 10) / 2 = 10.75 % ethanol instead of the expected 10%. If you filled your FJR (usually at least 5 gallons) you would get (.3 x 15) + (4.7 x 10) / 5 = 10.3% ethanol.
Doesn't seem like that big of a deal to me especially since there usually isn't exactly 10% ethanol in E10 fuel (that's just the max they can blend in). But stopping at only "dedicated hose" (non-blending) stations would be a way to avoid the whole thing.
Doesn't seem like that big of a deal to me especially since there usually isn't exactly 10% ethanol in E10 fuel (that's just the max they can blend in). But stopping at only "dedicated hose" (non-blending) stations would be a way to avoid the whole thing.