If a gas pump only has one handle, is there residue from different octanes in the pump / am I necessarily getting "my" octane?
At this sort of gas pump that only has one hose for all the gas types, does the gas I chose stay in the hose after I stop pumping?
If the next person chooses a higher octane gas, are they getting one hose-length’s worth of lower octane gas before they get their own?
This question is in the General Section. Responses must be helpful and on-topic.