David S. Wallens
David S. Wallens Editorial Director
8/21/19 1:08 p.m.

Do you run non-ethanol gas or not? Do you care? Does your car care? Look for some chat on the subject in the next issue of Classic Motorsports.

I filled up this weekend. We have a station nearby that offers ethenol-free 90 octane. Price was $3.15/gallon. Their standard midgrade goes for $2.64/gallon. 


frenchyd UberDork
8/21/19 2:08 p.m.

In reply to David S. Wallens :

I’m sorry David,  I like what GRM  magazine  proved. E85 makes more power!! Roughly 10% more power! 

 While there is an issue of Ethanol alcohol absorbing water over time the simple fact is gasoline has always had water in it. Older 40’s early 50’s cars often had a glass bowl on the firewall so you could tell how much water was in the gas. They even frequently had a drain to drain excess water.  

Now a lot of people will confuse methanol with ethanol.  To those I’ll explain that one is good for your car and one is bad.  

Methanol is poison, drink it and first you will go blind and then you will die.  Methanol will corrode aluminum and other metals

Ethanol is in beer, wine, booze. 



wlkelley3 UltraDork
8/21/19 8:18 p.m.

In my newer cars I do run gas with ethanol. Fuel systems in those cars are designed to run with it. Usually 90-91 octane mid-grade in the daily's and 93 octane premium in the autocross Miata. Running mid-grade is a carry-over from an old 81 K5 Blazer w/inline-6. It would ping with anything less than 89 octane so just ran mid-grade all the time. Did a test on another car and it got better mpg with mid than regular. Enough difference to justify extra cost of mid? I never calculated that. 

My classic (70 Opel GT) I run ethanol free premium in it. It doesn't get driven a lot and I only fill it up a 2-3 times a year so cost isn't too much of a concern to have the piece of mind that ethanol won't hurt the older fuel system.

There are 2 gas stations around me that sell ethanol free gas. One only sells it in premium 93-octane which I run in my Opel and the other sells it in regular 87-octane which I get for my lawn mowers. Have went through a couple mowers that ethanol gas messed up the carbs on. The newer one supposedly can run ethanol gas but suggest ethanol free so when it became available I started getting it for the mowers. Large yard plus my old age with bad knees means a rider for the large areas and a self-propelled push mower for the tighter areas plus weedeater and a tiller for SWMBO's garden and a pressure washer.

alfabeach New Reader
9/2/19 5:04 p.m.

I run ethanol-free 90 octane in my 1989 Alfa Spider. The car was designed to run regular, but I only drive a couple thousand miles a year. Why take the chance on gumming up the fuel system.

HundredDollarCar New Reader
9/3/19 9:35 p.m.

I ran 93 Octane ethanol free for years in the wife's R56 MINI, the Porsche and a E36 328is before I sold it.  The BMW was regularly used for interstate commuting and I could pretty well document a noticeable MPG increase over ethanol contaminated petrol.  It was nice living about two miles from the Riverside Market on a very active boating river.  Price differential over E10 was not that radical (lots of refineries in the immediate area, so low transport prices).  The price differential was just about spot on with the increase in efficiency and mileage IIRC, so you pay for what you get.  Now we live in a place where they sell ethanol-free gasoline in volumes for chainsaws and lawnmowers, and no premium grades - just 87 octane.  Huge price. 

David S. Wallens
David S. Wallens Editorial Director
9/4/19 12:46 p.m.

For me, with the Porsche, it's a storage thing as, sadly, the car sits a bit. (I know, I'm the worst.) 

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