Project 911: What Gas Do You Use in Cars That Sit a Bit?

Our 1984 Porsche 911 Carrera isn’t a daily driver and, we admit, does sit a bit. Since today’s ethanol-enriched gasolines can absorb moisture from the air, especially in an older car that doesn’t contain a fully sealed fuel system, we have been running non-ethanol fuel in the Porsche.

Three realities about that decision, though: non-ethanol fuels can be more expensive and harder to find than traditional pump gasoline while usually not offering a 93 octane option. 

We use the to find non-ethanol fuel locally. The site offers a mobile app, too.

Four local options cover our bases: 89 octane from Wawa, 90 octane from Mobil, 91 octane from Sunoco, and 93 octane from Cunningham’s Gas & Grills, a local barbecue supply house. 

The 93 octane sounds like a wish from above, but it’s not exactly an inexpensive option while the shop isn’t open all the time. So, our reality is a mix: 93 octane when the stars line up and 90 or 91 octane most other times. 

Another option: Sunoco Race Fuels offers Optima, a 95 octane fuel that doesn’t contain ethanol. 

Does running non-ethanol fuel really matter? All we can say is that in all these years, we haven’t encountered a fuel-related issue.

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alfabeach New Reader
1/2/20 12:58 p.m.

I use non-ethanol in my 89 Alfa. Most of the Gate Stations near me have it. It is usually about 15 cents a gallon more than premium.

alfadriver MegaDork
1/2/20 1:49 p.m.

In my '73 GTV, I've never worried about it- even with winters here in Michigan, I never had problems in the spring with the car.  And now that the car has sat for quite a few years without a fill up, it still starts right up, and does not have any problems.

While alchohol does absorb water, if the system is already robust, it's not a big deal.  As I see it and have experienced it.  Heck, I had to open the tank in my Miata, as the fuel pump siezed, and was amazed how clean that was after sitting half full for many years.

elwoodboll New Reader
1/2/20 2:11 p.m.

I'm constantly having to rebuild carbs on my 60s Mustangs because of the lousy, ethanol-laced gas here in Kalifornia.

David S. Wallens
David S. Wallens Editorial Director
1/2/20 2:35 p.m.
elwoodboll said:

I'm constantly having to rebuild carbs on my 60s Mustangs because of the lousy, ethanol-laced gas here in Kalifornia.

Does the site/app list any local stations serving non-ethanol fuel? I found the one pictured above thanks to the site. It's almost kind of in a residential area. I never would have found it if not for the site. 

1/2/20 4:11 p.m.

Fortunately, in my area there is the option of pure 87, 90, and 93 and I have use for each.  I understand pure gas can last up to two years if stored properly.  One thing to consider and that I contemplate is the extra energy level in pure gasoline compared to ethanol laced gasoline.  I can comment that my vehicles start and run better; holding gears longer while crusing before requiring a downshift using pure E0.  And of course more mileage per tank.  I understand that volumetrically, due to a change in the stoichiometric ratio with the introduction of alcohol the requirement for oxygen lessens and more fuel should be able to be introduced that would theoretically  offset the lack of energy in the alcohol, but can a modern gasoline engine adjust enough to make up the difference in an e10 fuel?  In other words, at WOT which fuel produces more HP E0 or E10 with no modifications to the modern fuel injected gasoline engine?

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