Leftover 2 stroke fuel as the cutting season ends

[rationull]

Now that I've done the majority of my brush clearing for the year (I hope) I've got to figure out what to do about my new trimmer and the leftover gas/oil mix. I've got some touch ups and other minor work still to do but that's not going to burn much fuel. After that it's possible that I'll have more to do later in the season but I'm not sure anything will really be required.

I was told that even with the stabilizer in the 2 stroke oil I bought the gas would only last 30-40 days. The left over half gallon of fuel I have is coming up on that age or might be older and I'm trying to decide what to do with it. My options are:

1) Keep it anyway and run it in the trimmer occasionally until the end of the season.
2) Dump it in our truck (big gas tank but doesn't get driven much so it would sit in there for a while).
3) Dump it in my car (smaller gas tank, smaller engine, etc. but driven every day so gas only lasts a week or two in it).
4) Dispose of it at the dump. This seems like a waste.

I think I like option 3 the best. But, should I worry about the leftover fuel doing any harm to my car given it's only mixed 50:1 with the 2 stroke oil?


As for trimming later in the season if I dump this stuff in my car, should I maybe try mixing just a half gallon at a time or just keep mixing one gallon and dumping the leftover in another vehicle?

I can't get anything other than E10 around here if that makes a difference.

 

[Oldmoparguy1]

I only mix a gallon at at time. Any left overs get dumped in my riding mower, Usually only a quart or less. If I had more then 1/2 gal. I would just dump it in my van. No big deal really.

 

[javacontour]

Originally Posted By: rationull
Now that I've done the majority of my brush clearing for the year (I hope) I've got to figure out what to do about my new trimmer and the leftover gas/oil mix. I've got some touch ups and other minor work still to do but that's not going to burn much fuel. After that it's possible that I'll have more to do later in the season but I'm not sure anything will really be required.

I was told that even with the stabilizer in the 2 stroke oil I bought the gas would only last 30-40 days. The left over half gallon of fuel I have is coming up on that age or might be older and I'm trying to decide what to do with it. My options are:

1) Keep it anyway and run it in the trimmer occasionally until the end of the season.
2) Dump it in our truck (big gas tank but doesn't get driven much so it would sit in there for a while).
3) Dump it in my car (smaller gas tank, smaller engine, etc. but driven every day so gas only lasts a week or two in it).
4) Dispose of it at the dump. This seems like a waste.

I think I like option 3 the best. But, should I worry about the leftover fuel doing any harm to my car given it's only mixed 50:1 with the 2 stroke oil?


As for trimming later in the season if I dump this stuff in my car, should I maybe try mixing just a half gallon at a time or just keep mixing one gallon and dumping the leftover in another vehicle?

I can't get anything other than E10 around here if that makes a difference.


No worries, dump it in.

Folks dump 16 and 32oz of MMO in gas tanks all the time with no ill effects. Dumping a 1/2 gallon of 50:1 mix into a 10-20 gallon tank probably won't even show up on the radar of your fuel injection system.

 

[dwendt44]

I've left gas/oil mix in the Lawnboy over winter several times over the years. Harder starting in the spring but it ran fine on that 'old' gas.
Were it me, I'd double dose with Stabil and make sure some of that gets down to the carberator.
Then either leave it as is, or dump gas out of tank and store till spring.

My 2¢

 

[IndyIan]

30-40 days seems a bit short for storage but better safe than sorry I guess.
What I do is get 91 or 93 octane gas and mix it at 40:1 so I'm not pushing the limits in terms of low octane or oiling for any of my equipment, and then use it for a few months.
If some is still left I dump it into the car or atv.

 

[willix]

I threw the snow thrower gas in the lawn mower and cut the grass 3 times. 50 to 1. no smoke. ran normal. starts on the first pull every time.

 

[javacontour]

Interesting question, does adding 2 stroke oil to the fuel raise or lower the AKI of the fuel.

My instinct is that the oil is more resistant to pre-ignition than the gasoline in which it's mixed.

But I could be wrong. I wonder what the AKI is for 2 stroke oil?

 

[Trajan]

If it's TC-W3, use it in the car at 1oz/5 gallons. TCW3 is ashless, cat friendly.

 

[IndyIan]

The octane gets dropped quite a bit with 2 stroke oil added. Actually it makes me think about how much oil to use, as I assume the more 2 stroke oil you use the lower the octane gets...
Maybe its possible to introduce preignition with the minimum spec'd octane gas and mixing oil in at 20:1 or even 32:1 instead of 50:1?

 

[javacontour]

If it were added in higher quantities, I could see that it would drop it significantly.

If one has 50 parts of 87 AKI and let's take the AKI for diesel to plug in for 2 cycle oil, so we have one part of 10 AKI "roughly" for diesel fuel.

Don't you simply end up with something on the order of 85 to 86 AKI?

Mix 1/2 gallon of that in with 10-20 gallons of 87 and you probably still have something close enough to 87. Probably end up with something close to 87 than 86.

I'm sure it's more complex than that, but I can't imagine 1 to 2 oz of two stroke oil mixed with 10.5 gallons of 87 AKI fuel is going to appreciably drop the AKI.

Because if you have a 50:1 mix and you have 64 oz of that mix, then you are not going to have more than 2 oz of oil in that mix.

 

[rationull]

Originally Posted By: Trajan
If it's TC-W3, use it in the car at 1oz/5 gallons. TCW3 is ashless, cat friendly.


This stuff had better be cat friendly given my trimmer has a cat!

Is it safe to say I'd probably notice running problems before it's too late if I just keep using this gas until the end of the season and *then* maybe put it in my car if any is left over? Or would it just gum stuff up out of the blue?

 

[OilNerd]

Most of my vehicles have 18 gallon tanks. At 40:1, there are 3.2 oz. of oil to a gallon. I usually dump up to a gallon, and fill -- a good UCL, and my car hasn't blown up yet.

Caveat: The small amount of ash isn't a problem for just a couple times a year, but I wouldn't do it on a regular basis. For regular UCL purposes, I use ashless TC-W3.

 

[mechanicx]

Why would 2-stroke fuel mix not last 6months-1 year with a good dose of Sta-bil?

 

[rationull]

Originally Posted By: mechanicx
Why would 2-stroke fuel mix not last 6months-1 year with a good dose of Sta-bil?


No idea. I haven't added any Sta-bil manually, though. The oil I got says it has a stabilizer in it.

 

[OilNerd]

For stabilizing E10, use the Sta-Bil Marine product. It's designed for ethanol use.

I can still get E0 gas where I live, so I use the regular Sta-bil, but I'm sure that there are some Sta-Bil Marine users here that could let you know how far you can push it with E10.

 

[Bror Jace]

Dump it in the car ... with anything over 6-8 gallons in the tank, the car won't notice a bit.

TCW-3 is ashless ... few if any metallic adds in the oil ... designed to burn cleanly in lower-operating temp, liquid-cooled engines.

 

[countryboy9799]

I am under the opinion that gas will last a long time if its in an air tight container. You say you may have some more work to later this summer, I would drain the trimmer if it was going to sit for more than 3 weeks. In my opinion gas goes bad much more quickly if exposed to air like it can in the carb.
As an example on my generator, that gas is 4 years old and still smells good, I treat it with pri-g every 6 months. You cant do that with stabil, that is only good for one treatment, maybe 2 but I cant remember. Now the gas in the carb will go bad in 30 days and thats why I shut the fuel off and let it run out of gas. I keep my 2 stroke gas for at least 6 months, I couldnt imagine getting gas every 3 weeks.

 

[IndyIan]

Originally Posted By: javacontour
If it were added in higher quantities, I could see that it would drop it significantly.

If one has 50 parts of 87 AKI and let's take the AKI for diesel to plug in for 2 cycle oil, so we have one part of 10 AKI "roughly" for diesel fuel.

Don't you simply end up with something on the order of 85 to 86 AKI?

Mix 1/2 gallon of that in with 10-20 gallons of 87 and you probably still have something close enough to 87. Probably end up with something close to 87 than 86.

I'm sure it's more complex than that, but I can't imagine 1 to 2 oz of two stroke oil mixed with 10.5 gallons of 87 AKI fuel is going to appreciably drop the AKI.

Because if you have a 50:1 mix and you have 64 oz of that mix, then you are not going to have more than 2 oz of oil in that mix.

http://en.wikipedia.org/wiki/Octane_rating#Examples_of_octane_ratings
On this wikipedia page it says the AKI requirement for a two stroke outboard motor is 67, and this sounds similar to something I read in a dirtbike magazine many years ago. 87 AKI turns into 70ish AKI with a typical gas oil mix. Fuel chemistry isn't all that simple I guess.

 

[JimPghPA]

Store the mixed gas in a cool place with no sun shining on the container and it will last longer.

 

[countryboy9799]

Originally Posted By: IndyIan
Originally Posted By: javacontour
If it were added in higher quantities, I could see that it would drop it significantly.

If one has 50 parts of 87 AKI and let's take the AKI for diesel to plug in for 2 cycle oil, so we have one part of 10 AKI "roughly" for diesel fuel.

Don't you simply end up with something on the order of 85 to 86 AKI?

Mix 1/2 gallon of that in with 10-20 gallons of 87 and you probably still have something close enough to 87. Probably end up with something close to 87 than 86.

I'm sure it's more complex than that, but I can't imagine 1 to 2 oz of two stroke oil mixed with 10.5 gallons of 87 AKI fuel is going to appreciably drop the AKI.

Because if you have a 50:1 mix and you have 64 oz of that mix, then you are not going to have more than 2 oz of oil in that mix.

http://en.wikipedia.org/wiki/Octane_rating#Examples_of_octane_ratings
On this wikipedia page it says the AKI requirement for a two stroke outboard motor is 67, and this sounds similar to something I read in a dirtbike magazine many years ago. 87 AKI turns into 70ish AKI with a typical gas oil mix. Fuel chemistry isn't all that simple I guess.


I go to several Stihl dealers and there is a sigh strongly recommending that you use 91 or 93 octane, I cant remember. They say not to use 87 or 89.