0
FlyingJ

Mixing fuel with/without ethanol - ok, not ok?

Recommended Posts

Question for those that know a lot more than I do about the topic...

Due to the detrimental effect of ethanol in outboard motors I make a point of filling up my boat at one of the local gas stations that sells ethanol free gasoline. I've never filled up my Jeep while at the station though as I was unsure if there is any detriment to going back and forth between fuel with and without ethanol.

If it matters, my Jeep is a 1996 Grand Cherokee with a 5.2L V-8.

Thoughts?
Killing threads since 2004.

Share this post


Link to post
Share on other sites
Quote

Question for those that know a lot more than I do about the topic...

Due to the detrimental effect of ethanol in outboard motors I make a point of filling up my boat at one of the local gas stations that sells ethanol free gasoline. I've never filled up my Jeep while at the station though as I was unsure if there is any detriment to going back and forth between fuel with and without ethanol.

If it matters, my Jeep is a 1996 Grand Cherokee with a 5.2L V-8.



The biggest issue with ethanol is it attacks hoses and seals differently than straight gas. The other thing is the slight difference in the way it burns. Most cars built within the last 5-10 years can deal with it both in hoses and seals as well as the computers that control mixtures for combustion. Most "reasonable" cars being built today simply do not care. Their computers will make the adjustments and you can switch back and forth or mix at will.

A normally aspirated, carburated engine from more than 15 years ago? It's probably not going to kill it, but if you haven't replaced the hoses and seals with modern ones, you probably will end up doing so a bit faster now. You're also not going to get an optimal fuel burn, but honestly, it's a 1996 engine and a number of ponies have left the barn anyway.
quade -
The World's Most Boring Skydiver

Share this post


Link to post
Share on other sites
Couple thoughts...

If you plan to leave your boat sitting for any length of time at all I would strongly suggest you either use a fuel stabilizer or fill with premium fuel first. Trying to ask your boat engine to make full power with fuel that has lost it's octane is baaaaad and will cost you a lot when the engine detonates (knocks).

If you go back and forth with a car from differing fuels you may get a "check engine" light due to the change in emission chemistry. More often than not it will be transient or go away next tank-up. I would expect and have not experienced any engine or fuel system problems going back and forth.

Completely different in certified aircraft. NEVER use fuel with alcohol in an a/c. You may get away with it for awhile but it'll catch up with you sooner or later.

jon

Share this post


Link to post
Share on other sites
One of the biggest problems with Ethanol that sits for a long period of time is that it becomes Hydrophilic ~ they will attract water which can really hurt your engine. (technically...compounds that have an affinity to water and attract water).
Fear is the thief of dreams.....

Share this post


Link to post
Share on other sites
Thanks everyone.

I always use non-ethanol in my boat, along with fuel stabilizer, etc. (though thankfully the fuel in my boat rarely sits long enough to need it).

Thus far I have just avoided filling the Jeep at the gas station that sells the non-ethanol fuel because I wasn't sure about mixing since I obviously won't have non-ethanol fuel available at all times. I guess I will give it a try and see what happens. I've ready various accounts of people getting an extra mpg or two running non-ethanol, but we'll see, I've read just as many from people saying they saw no difference. I will take anything I can get with a 50 mile commute in a vehicle that gets 16mpg with a 15mph tailwind.
Killing threads since 2004.

Share this post


Link to post
Share on other sites
Heres great site help with this. As a marine mechanic ethanol plays havoc on boats. Main things to avoid, don't add anything to ethanol based fuels designed to clean the fuel system of water. since most of these products are alcohol, the added alcohol will absorb more water in form of condensation. Gasoline with ethanol added shelf life is 3 months, it can absorb massive amounts of water. Staybil will not stop the moisture from being absorbed so it wont prolong the life of fuel very long. Staybil's purpose is to prevent oxidation, on non ethanol fuels its very helpful. Switching back and forth causes no harm except on older cars, as was said its hell on seals and hoses.

http://www.fuel-testers.com/expiration_of_ethanol_gas.html
Avoiding danger is no safer in the long run than outright exposure. Life is either a daring adventure, or nothing.”

Share this post


Link to post
Share on other sites
Quote

One of the biggest problems with Ethanol that sits for a long period of time is that it becomes Hydrophilic ~ they will attract water which can really hurt your engine. (technically...compounds that have an affinity to water and attract water).

I always figured on advantage to ethanol in the gas was that it carried any water in your fuel system thru the engine and out the tail pipe. Of course, too much water at once could be very problematic.

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

0