Topic: Filling up for first time - the advantages of ethanol free gasoline?

[kyle750]

Getting ready to fill up the newly installed Yamiya tank for the first time.  Like everywhere in the world the vast majority of fueling stations where I live sell a standard ethanol mix gasoline.  Called gasahol E10 in Thailand it is a mix with 10% ethanol and currently gas stations are moving toward E20 with up to 20% ethanol.

I found a Caltex station on the main highway not far from my home  that carries 95 Benzene/Techron Gold 95 (yellow pump) which is a pure ethanol free high octane gasoline with a 0% ethanol content. 

Should I go the extra distance and fill the CB750 with the ethanol free pure gasoline? What are the advantages of ethanol free gasoline?  Thanks!

[bender01]

Yes. Tools and toys always!

[Ozzybud]

I suggest only using ethanol free with every fill up.  The ethanol in the fuel absorbs water and if used in a daily driver it is not a problem. Our bikes used infrequently the moisture from the air in a half tank of gas will become part of the fuel and settle to the bottom causing rust and corrosion. I only use ethanol free in my bikes,classic cars and lawn equipment. Especially in Thailand where you have high humidity.

[grcamna2]

I suggest only using ethanol free with every fill up.  The ethanol in the fuel absorbs water and if used in a daily driver it is not a problem. Our bikes used infrequently the moisture from the air in a half tank of gas will become part of the fuel and settle to the bottom causing rust and corrosion. I only use ethanol free in my bikes,classic cars and lawn equipment. Especially in Thailand where you have high humidity.

+1

[Deltarider]

The answer is: NO. Ethanol in fuel is actually preventing rust in your tank. In ethanol free gas, water sinks to the bottom of your tank, where it causes building of rust. Ethanol binds the water so it does no harm, not until phase separation occurs. That risk exists if you let your tank sit for months partially filled so the maximum capacity of absorbing water by ethanol has been exceded. That has to be prevented.
Unfortunately there is a lot of hysteria in the internet. Realise that most 'gas treatments' products to fight the 'bad effects of ethanol' are actually containing quite some alcool themselves to enhance absorbing water. I've posted regularly on the matter. Look it up and you will be informed.

[kyle750]

Quick AI check with the following question:  Is ethanol in fuel actually better in preventing rust in your tank?

Here is the answer:

No, ethanol in fuel is generally worse for preventing rust in a fuel tank, especially in older vehicles or equipment that sits for long periods.
 
While ethanol itself is a strong solvent that can clean away existing gums and varnishes, its chemical properties actively promote new corrosion in several ways:

Moisture Attraction: Ethanol is hygroscopic, meaning it attracts and absorbs water from the air. This moisture condenses inside the tank and on its walls, directly causing rust on steel and iron components.

Phase Separation: If enough water is absorbed, the ethanol and water will separate from the gasoline and sink to the bottom of the tank. This concentrated water-ethanol mix is highly corrosive and can eat through metal fuel tanks, fuel lines, and injectors.

Acidic Byproducts: Ethanol provides a food source for certain bacteria (Acetobacter) that produce acetic acid as a byproduct. This acid vaporizes and can corrode parts of the tank both above and below the fuel line.

Corrosive Elements: Ethanol-blended fuels may contain trace amounts of chloride ions and have higher oxygen content than pure gasoline, both of which accelerate the oxidation (rusting) of steel tanks.

[Deltarider]

You, as well as AI* have harvested internet nonsense, not what scientists have found. You may want to be further infromed: http://forums.sohc4.net/index.php/topic,206216.msg2333025.html#msg2333025 and
http://forums.sohc4.net/index.php/topic,206216.msg2333063.html#msg2333063
* Since when is AI the bench mark for knowledge? I'm actually surprised your AI has not listed ethanol as an 'illegal alien'. Gimme a break!

[kyle750]

Just checking the accuracy of the answer on another AI database that relies on high-quality scientific data and ignores general internet content.

Is ethanol hygroscopic?

Yes, ethanol is hygroscopic, meaning it readily attracts and absorbs moisture (water vapor) directly from the surrounding atmosphere.

Key Impacts of Ethanol’s Hygroscopy

Difficulty in Purity: Because it absorbs water so easily, it is difficult to maintain "absolute" (100%) ethanol; once exposed to air, it will eventually settle at a concentration of about 95.6% ethanol and 4.4% water (an azeotrope).

Fuel Phase Separation: In ethanol-blended gasolines (like E10 or E85), the ethanol can absorb enough moisture to cause "phase separation," where the water and ethanol separate from the gasoline and sink to the bottom of the tank.

Corrosion Risks: The absorbed water can lead to rust and corrosion in fuel system components, particularly in older engines, boats, or equipment stored for long periods.

[PeWe]

Re-jet carbs if going to E10 from almost none.

Read the "Rides for Frank 2025" thread where Stu rode in Kansas on his Goldwing with E15 fuel.
A massive increase in fuel consumption!!!
No carbs, fuel injection, O2 sensor that helped the system to add fuel for programmed AFR.

I doubt the rubber in carbs, boots like the ethanol.

Methanol raced bikes change oil rather often if I have got it right.

Cars on E85 were often described as having issues with frequent oil changes and rubber that had short life.

Cars here were sold with a price reduction if possible to use E85. Most owners used std gasoline.

[jlh3rd]

was gonna say the pretty much the same thing as pewe.
Less mpg with ethanol vs non ethanol fuel.
generally speaking, seals, fuel lines, rubber, etc. don't like alcohol. Alcohol is a corrosive, even with some metal lines.  I'm assuming newer vehicles are designed to tolerate alcohol. I'm sure that honda's replacement fuel line is rated for ethanol fuels but my '75 bike still has all original everything, so no ethanol for mine.

If you ride a lot, 10% or less ethanol probably ok. All bets are off with the newer ethanol concentrations.
Curious what vintage Honda rebuilders have to say.

[jlh3rd]

furthermore, concerning "water" and fuels.
Piston Airplanes burn straight gas. There are drains at the lowest point of the tanks. They are water drains. The water comes  from condensation, either sitting and/or the warm/cold environment the fuel is subjected to in flying. Yes, the tanks are a rubber bladder and the tanks are vented, still happens. But it's not a phase separation phenomena.
Which IS the problem with ethanol.....in addition to condensation.

So, pick your poison?

[BenelliSEI]

Kyle…… around here there is also one place where I can buy ethanol free. When touring around the province I often am forced to use “up to 10%” as that’s all that’s available. I then try and do the final fill on ethanol free, on the way home. I also buy containers of the ethanol free for equipment around the farm, out of habit.

It’s like oil choices. Read all the opinions and reports, then make your own.
     

[kyle750]

There are many, many people on this forum that I have complete trust and confidence.   I respect all opinions (even if different from the majority)  but I hold your opinion in the highest regard. Thank You!

[Rayzerman]

Ethanol has a limit for water dispersion at ~4.5%.  Tends to phase separate after a couple of weeks or more.  No problem in using E10, but if not using it as a daily rider and bike is going to sit for any length of time, best add some isopropanol or Seafoam to the fuel.  Don't need a lot, as isopropanol can disperse many times the water that ethanol can.  A couple or three ounces in a tank will do the trick.
I'm in an area where E10 is now mandated, so no ethanol-free available....

[kyle750]

I am currently reading about ethanol and engine knocking (a highly destructive problem that can have devastating consequences).

Ethanol can indirectly cause knocking in older engines due to a Lean Mixture/Fuel Starvation. Ethanol requires a different air-fuel ratio than gasoline. Older engines with carbureted systems may not be tuned to handle this, leading to a "lean" condition (too much air, not enough fuel), which creates high cylinder temperatures and causes knocking.

Ethanol blends have lower boiling points, which can lead to vapor lock in older, hotter engines, causing them to stutter, stall, or knock under load.

Knocking creates severe, high-pressure vibrations that can bend connecting rods, shatter pistons, crack cylinder walls, and destroy bearings, leading to immediate engine failure or catastrophic, costly damage.

[kyle750]

Risk vs Reward

It looks like using ethanol blended gasoline in a Vintage Honda comes with a large number of additional risks.  The only reward I can see is it is better for the environment but not better for the bike   

[PeWe]

I like ethanol
Navy strength gin is my new favourite Friday after work drink. Mixed with Indian tonic water. Plus lemon slices and ice.
My bikes and car should not get it. As little as possible.

[Stev-o]

Although I haven't had an issue of rust caused by ethanol, it harms carburetors through the formation of hardened deposits (gum/varnish).  Typically it clogs the slow jet first causing hard starts.  I've also had to service the carb on my classic car due to eth, it unfortunately sometimes sits too long.

If it all possible, I always fill my bikes with eth-free, luckily there is a pump a mile from my home.

And all of my gas powered tools only use eth-free....

[PeWe]

Risk vs Reward

It looks like using ethanol blended gasoline in a Vintage Honda comes with a large number of additional risks.  The only reward I can see is it is better for the environment but not better for the bike

I doubt it is any environmentally positive effect.
If the engine has a perfect combustion it will run better with less pollution.
Ethanol has a cooling effect and will cause soot and carbon in the chamber, on piston crowns and valves if I have got it right.
TV shows and info on the Internet have given me that idea.

CO2 is a good gas for life.
Carbon dioxide is fundamental to photosynthesis.

There is other bad stuff from exhaust when not correctly adjusted or using bad fuel.

A CB750 takes rather much fuel. There are cars that consume less

Rebuild kit for reducing fuel consumption by 50% ?

[kyle750]

If the engine has a perfect combustion it will run better with less pollution.

100% agree

[MauiK3]

I used to own a 2009 Honda Ruckus, 49cc's of raging, quiet, power :-)). It was actually a great scooter but with 49cc's there was little power to spare. Running it on E10 it seemed to be very lethargic. When I switched to E free 89 it came alive. Great bike, for its intended use.
I don't use ethanol in any of my bikes or small engines. I keep some around for emergency because it has a longer shelf life.
There is less energy in equal amounts of E10 than what is in ethanol free gasoline.
Keep E10 out of your small carbureted engines as much as possible. If you are going to burn right through a tank, fine, storing it for a longer period, not so much.

[jlh3rd]

"CO2 is a good gas for life.
Carbon dioxide is fundamental to photosynthesis."

and to a Gin Fizz. 😂

they should ban electric car windows however...😉

[Don R]

 It's just my opinion, I use alcohol free gas when possible and add a couple oz of synthetic 2 stroke oil per tank to help protect the tank and exhaust.