Ethanol Fuels and Carb Deposit Differences

[wings&wheels]

I had a stuck float valve on my TR6 and pulled a carb that was untouched since rebuild ~6 years ago. I opened the carb to get to the valve and was shocked at the almost complete lack of deposits, see the pic below. The other pic is from the same carb in 2016 when I removed it for rebuild after ~8 years in service.

I use Redline Lead substitute and MMO in each tank and until 2016 used StaBil Storage for the off season. (The MMO isn't for any engine benefit; many, many years ago a sage old Brit car guru recommended it to help prevent the 'water line' rust that TR's (and MGB's) tend to get above the full line in their bare steel tanks, he felt it left a slight film, but I digress.)

In 2017 I started using StaBil Marine in every tank, and that is the only difference in fuel between the earlier interval and now. The car saw the same usage, ~700miles/year, hibernates, etc. and fuels up at pretty much the same two stations most of the time.

I am at a loss to explain the difference, and I have trouble believing it was just the StaBil Marine...

Thoughts?

Now;

2016/2017;

 

[oldhp]

You pretty well proved "StaBil Marine" works.

 

[SubLGT]

What brand gasoline?

 

[wings&wheels]

What brand gasoline?

Exxon and Shell mostly

 

[wings&wheels]

You pretty well proved "StaBil Marine" works.

Thanks, but did I? I guess I have a hard time believing that anything would make that much of a difference, especially based on a sample size of just me, but you are probably correct. Either way, I am not changing anything I am doing!

 

[sk_pete]

I guess metal surface deactivators. And antioxidants.
Maybe something more..
it looks like sulfur dust but probably it´s not.

 

[mfewtrail]

I am at a loss to explain the difference, and I have trouble believing it was just the StaBil Marine...

Thoughts?

Take a sample of the fuel the next time you fill up the car(or when filling up your gas can at the same station) and confirm that it actually has ethanol in it.

 

[Scuder]

I love the stuff. Years ago, it cured a bad start/run problem I had in a Cub Cadet when E-10 was introduced. I still use it in all my carburated engines, although only before winterization due to the availability of E-0 fuel in my locality.
Earlier today, I spent $50 on ten gallons of E-0 92 octane for my 10.5:1 Barracuda. Worth every penny in smiles per gallon.

 

[incognito_2u]

That’s a night and day difference right there!

 

[mfewtrail]

Take a sample of the fuel the next time you fill up the car(or when filling up your gas can at the same station) and confirm that it actually has ethanol in it.

I meant to quote your other post about "exxon and shell" when I said that. Several years ago I tested a sample from my local Shell station and found it was ethanol free. The sample I tested was purchased at the beginning of Fall for what it's worth. I never did any followup testing to see how often they had ethanol free fuel at the pumps though.

 

[bobdoo]

I ran non-alky premium and Stabil marine in my boat. It sat in my backyard for something like 8 years, and when I put it back in service, I also pulled the carb apart.

Just like yours, it was spotless and brand-new looking inside.

 

[GR_CoB]

My small engine carbs stay this clean with MMO. But did have deposits before I started using MMO regularly. After storage also crank up quick without any trouble.

 

[svtrit]

I’ve always used E85 as a carb CLEANER. I’ve fixed many a chainsaw and go-kart by soaking the carb in E85 overnight. I ran a tank of E85 in my 95 Wrangler as a cleanser as well. It prefers non-ethanol fuels, but had no issues.

E10 is the prominent fuel here and I’ve never had an issue. Interesting what these pictures show.

 

[wpod]

Looking at the carb keep on course.

 

[64bawagon]

No matter what anecdotal evidence is presented here I think you already know what works for you, hard to argue results like that.

 

[Wolfshead]

"I tested a sample from my local Shell station and found it was ethanol free'
How can one test Non Eth.gas to be sure it really is Non Eth.?

 

[Skippy722]

"I tested a sample from my local Shell station and found it was ethanol free'
How can one test Non Eth.gas to be sure it really is Non Eth.?

Quick and dirty test would be to just add some water to the gas in question in a bottle. You’ll have a water level, an ethanol level if there is any in there, and the rest will be gas. Or you can spend $15 and get fancy

 

[midnightlaundry]

Did a Chat GBT inquiry and Marine is the bomb, but is most expensive..

Perfect — here’s a full side-by-side chart of the three main STA-BIL products:

Feature	In-Season (Gold/Green)	Marine (Blue/Green)	Storage (Red)
Primary Use	Everyday driving & small engines during active season	Boats & marine engines in wet/humid conditions	Long-term fuel storage (cars, mowers, generators, seasonal vehicles)
Focus	Keeps fuel fresh, prevents deposits, cleans system	Heavy-duty corrosion & ethanol protection, water defense	Preserves fuel stability for long storage
Corrosion Protection	Standard	Enhanced (saltwater & high-moisture environments)	Good (but less robust than Marine)
Ethanol Defense	Helps reduce issues	Superior — prevents phase separation	Helps reduce issues
Detergents	Yes — keeps system clean	Yes — stronger cleaning power	Minimal (focus is storage, not cleaning)
Fuel Freshness Duration	Up to 12 months	Up to 12 months (sometimes noted slightly longer)	Up to 24 months
Best For	Cars, ATVs, motorcycles, lawn equipment used regularly	Boats, jet skis, inboards/outboards, high-humidity use	Vehicles/equipment in seasonal or long storage (classic cars, snowblowers, backup generators)

 

[mikeduf]

I ran my tank down to about 1 gallon of gas, and it seemed to run okay with the 10% ethanol. I think most modern engines will run fine on 10%.. your fuel economy will probably take a hit in hot weather. I have not contributed to Consumer Testing of 15% ethanol yet. It seems we are the testing grounds for all of this stuff going on today but I digress.

 

[Nessism1]

Did a Chat GBT inquiry and Marine is the bomb, but is most expensive..

Perfect — here’s a full side-by-side chart of the three main STA-BIL products:

Feature	In-Season (Gold/Green)	Marine (Blue/Green)	Storage (Red)
Primary Use	Everyday driving & small engines during active season	Boats & marine engines in wet/humid conditions	Long-term fuel storage (cars, mowers, generators, seasonal vehicles)
Focus	Keeps fuel fresh, prevents deposits, cleans system	Heavy-duty corrosion & ethanol protection, water defense	Preserves fuel stability for long storage
Corrosion Protection	Standard	Enhanced (saltwater & high-moisture environments)	Good (but less robust than Marine)
Ethanol Defense	Helps reduce issues	Superior — prevents phase separation	Helps reduce issues
Detergents	Yes — keeps system clean	Yes — stronger cleaning power	Minimal (focus is storage, not cleaning)
Fuel Freshness Duration	Up to 12 months	Up to 12 months (sometimes noted slightly longer)	Up to 24 months
Best For	Cars, ATVs, motorcycles, lawn equipment used regularly	Boats, jet skis, inboards/outboards, high-humidity use	Vehicles/equipment in seasonal or long storage (classic cars, snowblowers, backup generators)

I use Marine. It's $9/quart more expensive compared to the regular stuff, but one bottle treats 320 gallons of fuel. Great stuff!