David S. Wallens
David S. Wallens Editorial Director
10/24/23 12:54 p.m.
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Our M3 didn’t sound so good as it coughed and sputtered after some laps at the FIRM. You know that queasy feeling you get when something really bad happens? That was us. Did we break it?


[Can our E46 M3 run with a new Hyundai Elantra N?]

The problem seemed to fix itself–did we j…

Read the rest of the story

dean1484
dean1484 MegaDork
10/24/23 1:14 p.m.

Some cars are very sensitive to old fuel.  Your car with plugs and coils that were in the latter part of their service life and fuel that is not optimal for it and it very well could be the problem.  I discovered that one of my cars will toss a misfire code if I run 93 octane.  Feed it 87 and it is happy.  

Brett_Murphy (Agent of Chaos)
Brett_Murphy (Agent of Chaos) MegaDork
10/24/23 1:40 p.m.

I had a big problem with phase separation in some of the fuel I got this summer. It seemed to get screwy just by sitting in a sealed gas can over three weeks or so.

I'm wondering if the humidity over the summer made some condensation build up in the can that just kick started the process quickly or something. 

kaybat
kaybat New Reader
10/24/23 1:53 p.m.

My S54 did this a few times a year(at start-up), turns out it needed a throttle body actuator(?)..Wilsons new right away.

David S. Wallens
David S. Wallens Editorial Director
10/25/23 8:16 a.m.

In reply to Brett_Murphy (Agent of Chaos) :

Maybe we had some phase separation? Somewhere in there we fueled up a few times with some fresh Sunoco so I’m driving the car a bit just to flush things now. 

Brett_Murphy (Agent of Chaos)
Brett_Murphy (Agent of Chaos) MegaDork
10/25/23 11:26 a.m.

In reply to David S. Wallens :

I read this article about it. In my situation, I put the bad gas into my lawn mower, and it ran (poorly) for a bit, then choked out completely. The carb bowl was completely filled with the water/ethanol phase.

I'd love to see phase separation among the gasoline articles you do, especially as many of us have cars with gas in them that sit around, unused, for weeks or more at a time.

David S. Wallens
David S. Wallens Editorial Director
10/25/23 11:35 a.m.

In reply to Brett_Murphy (Agent of Chaos) :

Like show a real example of phase separation? Let me talk to Zach about the realities. My fear is that it might vary due to fuel, container and conditions, but let me ask.

David S. Wallens
David S. Wallens Editorial Director
10/25/23 11:36 a.m.

By the way, as of this morning, the M3 starts and idles just fine.

Car is running Sunoco 93.

Brett_Murphy (Agent of Chaos)
Brett_Murphy (Agent of Chaos) MegaDork
10/25/23 11:50 a.m.

In reply to David S. Wallens :

Maybe talk about what it is, how it happens and how it can bit us in the ass if gasoline sits around for a while.

Tom1200
Tom1200 PowerDork
10/25/23 11:54 a.m.

In reply to Brett_Murphy (Agent of Chaos) :

Everything I have that sits for even a short length of time gets quality fuel. In my case it's 100 octane unleaded (available at the pump).  I put it in everything from the mower to the races cars to the dirt bike................I even use it in my portable generator.  

Since I started doing this I've had none of the small issues I had before.

 

David S. Wallens
David S. Wallens Editorial Director
10/25/23 1:18 p.m.

We’ve written about fuel aging before, and see if these articles help answer some questions:

What Happens to Gasoline as It Ages?

Antioxidants, Fuel Stabilizers, and You

How fresh is that fuel?

The right fuel in the fall might help your engine start in the spring

Fuels for storage: Good, better, best

Water Is Great for Your Plants, Not So Much for Your Fuel System

Should you fill up your classic before parking for the winter?

But it sounds like maybe there are still questions about this. (For the record, I try to put Sunoco 93 in everything since, like Zach always says, a Top Tier, high-octane fuel will simply age better.)

Brett_Murphy (Agent of Chaos)
Brett_Murphy (Agent of Chaos) MegaDork
10/25/23 1:30 p.m.

In reply to Tom1200 :

I try to use the best ethanol free I can get around here if it's going to be sitting. I tried to cheat a bit and was surprised at how quickly it went bad!

 

Brett_Murphy (Agent of Chaos)
Brett_Murphy (Agent of Chaos) MegaDork
10/25/23 1:33 p.m.

In reply to David S. Wallens :

I saw a couple of those, but didn't realize there were so many (or had forgotten about them). Thanks!

David S. Wallens
David S. Wallens Editorial Director
10/25/23 2:27 p.m.

In reply to Brett_Murphy (Agent of Chaos) :

Cool, glad they helped. This one might lay out the best plan for fuel for storage: Fuels for storage: Good, better, best.

David S. Wallens
David S. Wallens Editorial Director
10/27/23 11:04 a.m.

Just had a good, informative chat with Zach at Sunoco about phase separation: what causes it, how to avoid it, and what to do when it happens. This one will be for Classic Motorsports. 

TL;DR: Drive you cars more. 

Brett_Murphy (Agent of Chaos)
Brett_Murphy (Agent of Chaos) MegaDork
10/27/23 11:27 a.m.

In reply to David S. Wallens :

And the only solution seems to be: Siphon it out.

Then, run it through the lawn mower, use it to start a fire, or take it to a hazardous recycling facility. 

David S. Wallens
David S. Wallens Editorial Director
10/27/23 11:31 a.m.

In reply to Brett_Murphy (Agent of Chaos) :

Not necessarily. Or, depends on the situation. 

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