Single-nozzle Gas Pumps

[Cujet]

Welcome to BITOG

The residual gas is minimal if that

My local Sunoco used to have bright yellow 93 octane fuel. The regular fuel was clear.

I'd fill my race jugs with fuel and well over a gallon came out before the fuel leaving the nozzle was completely bright yellow. One day I saw a pump being repaired and noticed the large 'spin on' fuel filter that was DOWNSTREAM of the mixing pump and connected to the hose. That filter held two or three quarts.

Because my turbocharged Honda S2000 needed all the octane it could get and had a small tank, I'd fill up a race jug with 93 before filling my car.

 

[Cujet]

The lower pump picture has 2 (one quart) filters. One for regular and one for premium.

My local Sunoco pumps have a single filter that is twice as tall. Hence the "over a gallon" before the 93's color is correct.

 

[Surestick]

Well perhaps not so in the US, but here in Ontario premium doesn't have any and I believe it's so for the rest of Canada.

Depends on the brand. Here in Alberta Shell 91 is E0, Husky and Fas Gas have the "may contain up to %10 ethanol on all the selections.
Check here though it's a privately run site so who knows how accurate and/or up-to-date the data is.
As above, I pump a couple of liters into my vehicle then fill the jerry can to make sure I'm getting E0.

 

[Pelican]

Depends on the brand. Here in Alberta Shell 91 is E0, Husky and Fas Gas have the "may contain up to %10 ethanol on all the selections.
Check here though it's a privately run site so who knows how accurate and/or up-to-date the data is.
As above, I pump a couple of liters into my vehicle then fill the jerry can to make sure I'm getting E0.

Yes I saw it today and stand corrected! It didn't use to be so, but it's so hard to keep up with all of these changes.

 

[Black Thunder]

I have yet to see a pump at any of the stations around me say that premium is ethanol free, everything is labeled E10.

In my area there are several stations that have 91 ethanol free Recreational gas.


there are also a few stations that have 87 ethanol free, which is generally the only gas that I buy

 

[DGXR]

I would run at least 1/2 gallon through if you want to be sure you're getting 100% selected grade in your fuel cans.

 

[Snagglefoot]

My best guess, it depends on the last customer. If they prepaid, the pump shuts off and the hose mostly empties into the tank. (Completely if they lift the hose so it's all above the nozzle before removing it). If they used a card or post-paid then the fuel was stopped at the nozzle.

There are probably other factors involved.

Here is an educational video how gasoline pump nozzles are designed. Once the pump is shut off the poppet closes you cannot open and drain the pump hose. Any extra fuel you think you are getting is just the small amount inside the body downstream of the poppet inside the handle. The pump has to be running with positive pressure to the handle to get the poppet open again.

 

[y_p_w]

I'd be highly skeptical that anything wouldn't test out at whatever grade was purchased as long as several gallons are pumped.

They send this stuff through pipelines where there's intermix. The tiny amount of the previous fuel that might mix in isn't going to make enough of a different to worry about. There isn't anything in an 87 octane fuel that isn't in a 91/92/93/94 octane fuel unless you're talking something containing 100 octane unleaded race fuel. As long as you're getting what you paid for, why worry?

 

[Snagglefoot]

Yes, it’s actually a bonus in the reverse direction. Get in line behind someone who bought premium and punch the 87 button. But, if anyone wants to suggest a hose ID and length, plus the filter dimensions and guess on a bit of piping, we could calculate how much fuel we are talking about.

 

[DGXR]

Welcome to BITOG

The residual gas is minimal if that

I agree. The only issue with blender pumps is for motorcycles or other vehicles with small fuel tanks. And even then, I seriously doubt any damage will be done by the relatively small amount of undesirable fuel remaining in the hose. Maybe if your bike has a 1 gallon tank, but that's just crazy.

 

[kschauweker]

Here is an educational video how gasoline pump nozzles are designed. Once the pump is shut off the poppet closes you cannot open and drain the pump hose. Any extra fuel you think you are getting is just the small amount inside the body downstream of the poppet inside the handle. The pump has to be running with positive pressure to the handle to get the poppet open again.