fuel talk/discussion

Separating water, yeah.

 

Most corporate gas stations will get a fuel dump daily or at the very most, weekly, of all grades and diesel. Premium and diesel may be purchased less often and sit longer in a mom and pop shop as they may wait for a favorable price and max out their underground tanks then. The big boys sell to themselves or have a contracted price that is good for x number of gallons so they get a little bit every time the tanker drops fuel. But the regular 87 is virtually guaranteed to be under a week from terminal to pump pretty much everywhere. Most gas stations "in town" carry under a week's worth of inventory of 87 at any given time. Many only a day or two - or less - due to volume restrictions vs what they sell.

 

In the presence of water ethanol can separate from gasoline in hours...less than a full day for sure.
Enough to cause individuals to not necessarily get "10% ethanol" in a given tank of fuel...more like 5% to 30% as was mentioned earlier...I dunno, just spitballing here, certainly seems plausible though...

 

Agree, depends on the volume the station does but I've seen trucks make deliveries at stations several times in a week.
Which brings up another point, I never buy gas at a station for at least a day after I see a fuel delivery.
I'll pass up that station if I see the fuel truck there and go elsewhere.
Not only for what brenndatomu stated but also for all the sediment that gets stirred up.
I don't trust the filters on the pumps.

 

Definitely plausible in a leaky tank, or a station with shoddy maintenance practices. Once water is in there in significant quantity, it will pair with the ethanol and drop to the bottom of the underground storage tank. In a modern, properly operated station the presence of a significant amount of water will set off an alarm in the tank monitoring equipment, and warrant a pump out of the water by a service company. If the water level is high enough to be near the pickup tube, the tank monitoring equipment should automatically shut down the underground pump. The very last thing a gas station can afford is the reputation hit of selling bad gas!

In addition the the tank monitoring equipment, stations should regularly be sticking their tanks with water finding paste smeared on the end of their measuring sticks to detect water in case of monitoring equipment failure. This can also show if phase separation of the gasoline/ethanol has occurred if the operator knows what they're doing.

Aside from actually sucking water, the risk of sucking "purer" gasoline is more dangerous to equipment without computer controlled timing than a higher concentration of ethanol. Ethanol has an octane rating of 115, so to achieve 87, the gasoline it's blended with has to be lower than the standard 87 rating most equipment is designed to burn. A modern car's knock sensor will goober (forum software is changing the word "r e t a r d") the timing instantly, but the ol' hot rod sure won't.

Regarding the question of why an unscrupulous terminal or blender would add extra ethanol despite its higher cost - there is a subsidy from .gov on ethanol. Some of the transportation companies I've dealt with actually provide the purchaser a breakdown of gallons on every bill of lading - e.g. 1000 gallons gasoline, 100 gallons ethanol.

Tl;dr version: buy gas from a big company, or an independent operator you trust.

 

For what it's worth, I started my Chinese push mower this week after sitting outside all winter with e-free Esso 91 octane and a dash of Seafoam in it. 3 pulls and it was running.

 

That is all I use as well OldJack. - 91 non-oxy and Seafoam. Never drain any power equipment and everything starts just fine in a couple pulls or so, even after sitting over the winter for 6 months in the case of my lawn mowers and outboards.