One can still buy Sunoco 100 octane at a few stations through out the county

or Spirit 100 octane race fuel.

The EPA does have a say in octane levels. 93 available in Arkansas, 91 in Oklahoma.
It has to do with air quality sampling. I fill my extra gas jugs just before going across the line.

Sea Foam
 

I use Sunoco 93 on the corner near my house. Along with all the doubt of gasoline quality and my gas gauge sticking, I'll be using a pint of Sea Foam once in a while. Guys at my local NAPA swear by it. They put it in gas motor they have....can't put too much in, they say. Seems to me, they are unbiased, so that's what I'll be doing as well. From my C5 to me lawn mower...............what say you? :toetap:

Wasn't always that way (at least in NJ). Sunoco used to deliver ONLY from their own refinery and in their own tankers.

I'm afraid that's also from the time when one station would always cut their price 1 or 2 cents JUST to be under the other down the road :yesnod:.
Now, look how many are ALL the same price. :willy:

Long ago I worked at a refinery as a summer job - it was "enlightening" to see the different trucks fill up there with the same gas; Exxon, Mobil, Texaco, Plateau, Shamrock, etc........ like others have said the base fuel was identical, with the only difference being additives specified by the various purchasers of the fuel.

Wouldn't use it
 

I know this thread is old but... In July of 2015 I went to Carlisle, they had a seminar and the subject of fuel additives was brought up. One guy said that he used Sea Foam. The senior tech that was there said NEVER use sea foam. It has corrosive ingredients in it that ruin electronics in the tank.Just putting this out there

I sell to the refining industry here in Texas and inside the gates every day. I've never asked who mixes in the additives but I can say that Techron solved an issue I had with a fuel gauge sending unit. Instead of buying a bottle of Techron I just filled up next tank and before 40% ran through it was functioning properly. I read about the Techron additive here on CF so tried it and it worked.

SUNCOR Energy in the list is Sunoco. In Canada it is marketed under the Petro Canada brand. Sunoco is Top Tier.

As I passed through NE, I noticed the pumps there (at the station I was fueling from) carried 87 w/o ethanol, 87 w/ethanol, and 91 octane (w/ethanol). So were the 87s closer in ethanol content than advertised? My pigs all take 91, so moot point for this guy.

E10 is bad. E15 is really really bad. None of our cars were ever designed for E15.

We can use E10 and have minimal problems.

Here in FL we're lucky to have Racetrac stations that sell ethanol free gas. The problem is the octane is fairly low (87 Octane).

Richard Newton

In Metro Detroit it is easy to find out which tank farm the gas comes from, one has 92 octane and the other sells 93 Octane. When I first started using some of the 92 octane, I ran into the fuel gauge problem--showing out of gas. Now I only use the 93 octane and have not had a problem in several years.

An N Gel, you map does not show the Enbridge crude pipeline crossing Michigan at the Straits of Mackinaw and going to Sarnia, Ont.