Found it. Since the gas goes through the same hose as the other blends, if you're buying gas you need to get at least 4 gallons so the previous gas flushes out what was left in the hose from the previous sale, and fills enough of the container that the blend is primarily what you selected.
If you buy E15 and fill your tanks, then the next guy buys E10 and only gets 1 gallon, they might end up with a higher ethanol mix than intended, and if they use that on a small motor, like a chainsaw, it could ruin the seals.
Multiple tanks hooked up to one valve and hose vs. multiple tanks with their own separate valves and hoses.
Obviously, it's a different kind of valve in the first setup to prevent backflow into other lines, but that's probably about the extent of it. With the second setup, you probably need to run a new line and pump for each station for each gas type, compared to just tying the tanks into the one valve and pump per station.
I'm not a plumber or anything, though, so take it with a grain of salt.
There are a few stations near me that have E85, "88 octane" (which is just 12% ethanol), diesel, and three grades of gasoline. Since you can't mix those other fuels with gas the pump has four hoses and you still have to select the grade of gas.
(US) I've been to gas stations in big cities, small towns, little collections of buildings that have no official name but they have a dollar general and a gas station, etc...
I've seen several kinds.
Single hose to dispense 87-93 ("normal") gasoline, and one for diesel
One hose for normal gas, one for diesel, and one for high-ethanol
One for all gasoline types and one for diesel
One super fancy stainless-steel-clad gas station that looked like something from retrofuturism had 5 hoses, one each for 87,90,93, e15, diesel, and the farthest end pump had a line for kerosine.
Here's a pretty typical american pump: https://www.alamy.com/stock-photo-shell-station-gas-pump-135764267.html
You can select diesel with the green button, which comes out of the green handled hose on the left, but any other option for regular gas (87/89/93 in that picture) comes out of the right hose.
In America drastically different fuels like E85 and Diesel are dispensed with different hoses as mixing those with normal gasoline or vice versa in the wrong system could cause damage. But when it comes to different grades of just gasoline it's all the same hose. E10 or E15 are pretty much standard in many parts of the Country of Corn (USA) so they are the primary form of gasoline available for normal cars.
Every fuel has its own hose and “pistol”. Each “pump” has two or three or four hoses.
While those do exist in the States too, a single hose and "pistol" is used for all grades of gasoline and the operator presses a button to select their grade of fuel. The only time there is a guaranteed separate is between desil and gasoline:
The button leads to some interesting minor social problems. The expectation is that the use uses their hand or fingers to press the button, but the buttons are usually disgustingly dirty, so that lead many to using the tip of the "pistol" to smack the grade of gasoline which may put a drop or two of gasoline on the button. So those that come next and use their hands end up smelling like gasoline.
No longer interacting with public gas pumps is one minor joy of driving an EV.
i'm gonna be real with you buddy i have never seen a "disgustingly dirty" fuel button so I think the people in your area just grody. no offense to present company.
You never hit up a Shell station? Majority of them and independents I’ve been to have buttons that are worn through on the octane text for low grade. High octane is usually next most worn
I'm in Australia and it's on the pumps—like little manufacturer stamps that don't seem to be aftermarket labels. Most people wouldn't notice it and those that do wouldn't understand what it means.
It's generally a tiny label like "Minimum 5L" or something, near the nozzle, or on/below the meters.
Diesel are often entire separate sections of the gas station.
Most of the pumps in the US have the same hose for 87/89/92 octane pumps that are E10 (10% Ethanol) and if there is a higher ethanol like E15 or E85, they're usually a separate hose.
I've seen pumps that have individual hoses for each octane grade in the US, but they're definitely uncommon, at least where I am, and I believe more prevalent on older pumps. But diesel always has its own hose.
Probably nothing. I guess it's possible if you kept switching back and forth between pumping a gallon of premium and a gallon of regular on different pumps to try to steal a few dollars of higher grade, they can use it to give you a ticket, but I'm pretty sure they won't really care if you were just topping off a tank of gas with 3 gallons before a road trip.
I honestly don't know what one does if one runs out of gas down the road from a gas station and doesn't want to call AAA or similar. I assume that gas stations must keep a jerrycan or similar around that they'll let someone take with a deposit.
I definitely wouldn't want to be lugging more gallons by hand than would be necessary to get my car to the gas station.
You'd be amazed how many people learn the hard way that they first need to head to a separate store to buy a gas container, then head to the gas station. Most places could care less about keeping a container on premises because it is both a rare situation these days, and storage is at a premium in most stores. If you saw the back room or manager's office, you would see the floor-to-ceiling stacks of inventory (usually drinks or tobacco products).
So, I don't know what the deal is with E15 -- what's unusual there is the ethanol content -- but insofar as high-octane blends go, and if that's the factor here...I mean, while I realize that there's a certain contingent of people who buy them because they think that they're just better for their car, and for all I know that may dominate the actual market, in theory you're supposed to only use high-octane fuels in cars with engines that require it.
I guess they'd probably function without it, but...
Generally higher octane works fine in most cars but high performance engines not configured to handle either type may knock with lower octane fuel (due to premature ignition with the higher compression ratio), and will generally put out (slightly) less power regardless due to timing adjustments the engine will make to accommodate the change.
Putting premium in a regular car that isn’t designed with higher compression ratios in mind is really just a waste of money.
As it's a federal regulation, it would need to be the feds pursuing it. It's highly unlikely they'd come after the individual. They would be more likely to pursue the gas station.
Around here stations have a purpose-built plastic bag that seals after filling up and fits in the car's fuel intake. It holds a few gallons, but I'm not sure how many.
I didn't know this before and it adds credence to my feeling that it's better to let my tank get below 1/4 full before filling it up, rather than continually topping it up.
Lower octane that puts in higher octane aren’t burning the fuel because higher octane needs a hotter spark to burn it all so you’re essentially wasting money or slowly killing your catalytic converter by putting in a higher octane than what your car is meant to use.
On the flip side, lower octane in a car that requires higher means the gas ignites quicker which will cause knocking and can damage the engine.
There’s probably more to it than this, but that is what I was always taught.
I fill up when I hit 1/4 tank as well. Don’t wait for it to go below though, as it can be bad for the engine with deposits and other stuff in the tank.
I would hope your car has a fuel filter installed that would never let deposits get to the injectors. (Or carb on the off chance you drive one of the last ones on the road.)
You should be filling up closer to a third. The fuel pump is cooled by the fuel and letting the fuel run too low can cause more wear and tear on the pump, causing it to fail.
Well, I just typed “1 gallon in liters” into google and took the first number, because I couldn’t be bothered to deal with your system of measurement more than necessary. My point stands regardless of the exact volume of one gallon.
OF COURSE THERE IS MORE THAN ONE DEFINITION OF GALLON
Portable US gas tanks are typically 1, 2, or 5 gallon.
I usually just grab a 5 gallon (about 20L) can to fill up my lawn mower, throw some fuel stabilizer in there, and then I don't have to go back to the gas station for a long time.