Most if not all gas pumps have a single hose for all three grades of fuel – regular, mid-grade and premium. The question is: when you switch between grades — if the customer before you used regular and you want premium — how much regular gas is stored in the hose and goes into your tank (at the premium price) before you begin to get premium gas?
Maybe not a big deal for cars, but for motorcycles with 4-5 gallon tanks, it might make a big difference.
Thanks — Luke
About a half a gallon. Look for a pump that was just used by a vehicle that bought premium
A gallon is about 230 cubic inches. How long is the hose and what’s its inside diameter.
If the hose is 10 ft (120 inches) long and has an inside diameter of 5/8 inch, then it would hold 36.8 cubic inches of gasoline or about .16 gallons.
I don’t worry about it because my current motorcycle, a Kawasaki ZRX 1200, runs just fine on regular and I don’t buy premium for it anyway but when I owned a '74 BMW R90/6, I made it a point to see what the last person bought or filled at stations that had three hose pumps.