GAS: Regular? Premium? Ethanol?

[scrappy isb67]

What is it? A diesel?

nope, it is a VW 2.0t gas engine. the 2.0t uses direct injection just like a diesel (but at much lower injection pressure) because if the direct injection, high compression is workable. (fuel can't ignite if it isn't in the cylinder) all on 91 minimum octane.

 

[radioman]

funny -- ever since my state added up to 15% ethanol to our gas --- I been getting in touch with my inner small engine mechanic side, learning every crook and nanny of little carbs and jets with all of my little engines. trimmers, tiller, chainsaws, hedge clippers,push mowers, etc . This is more then I care for to do but being poor can just makes you learn. :thumbsup:

 

[s219]

I really wouldn't worry too much about octane for 2-strokes -- it's a much smaller factor than ethanol. I'd take 87-octane ethanol-free over a 93-octane ethanol-blend any day. Ethanol gas is just pure evil for 2-stroke power equipment.

 

[murphy1244]

the wife's car is turbocharged and running 12:1 compression. just because it is turbocharged does not mean it is lower than NA. especially in modern engines.

No way in heck its 12 to 1 in a turbo or any usual car.

 

[ruffdog]

"The cooling effect of directly injecting fuel into the combustion chamber lets VW get away with a high-for a turbocharged engine-compression ratio of 10.3:1."
2006 Jetta 2.0 turbo

 

[ruffdog]

The 2013 beetle 2.0 turbo is running a 9.6 : 1 compression ratio

 

[ruffdog]

The problem with ethanol and 2-stroke premix is as the ethanol absorbs moisture, it will start to separate the oil out. With non ethanol fuel, the water would just sit on the bottom. With ethanol, it gets absorbed and pushes the oil molecules out. That is why, with ethanol, you should always use fresh fuel.

 

[joshuabardwell]

That's interesting that turbocharged engines don't typically run higher compression than NA engines. Did that used to be the case? Seems like the whole point of a turbocharger is to allow running a richer mixture, which would require higher compression to combust. But I guess nothing's stopping an NA engine from being designed to run in that same state.

What do you think about my argument about octane, though? Do typical 2-stroke engines run high enough compression to benefit from higher-octane gas? I've done some web searching and found at least one person who says his Stihl chainsaw says 93 octane right on the gas cap, but other than that, nothing but people asking the question and getting mixed answers, just like on here.

 

[cropdusting]

I saw this thread and thought I would throw my OPINION into the ring with everyone elses, but my opinion comes from maybe different experiences. From the below pictures you will see I have a lot of different gasoline engines all requiring different lubricants and fuel requirments. As you can see a "one size fits all" doesn't work for me.

My main race bike (I have others) because of its high performance (14.5:1 compression, 45 rwhp verified at 5,550 ft elevation) and relatively narrow operating range it is the most fuel sensitive (jetting, altitude, air temp and density) of all my bikes. So its performance will vary if consitant fuel (and jetting) is not used. Idealy I use VP 110 or C12 leaded non-oxygenated fuel and jet for that, however I can use with some success and minimal performance loss 93 pump gas with an octane boost, ethanonl does not seem to matter other than the lower performance. I do have to rejet for fuel changes though. My mix is 40:1 with full synthetic with caster oil.

The bike on the liftis a similar type of engine only I jet for using 93 pump and same oil, its engine porting characteristics lends itself to slower speeds as it is my "trail/play" bike.

Both of these bikes don't really have a preference for fuel

My trials bike(s) as I have two, these require premium pump and octane boost gas at least, they run decent on ethnol as they are low rpm 2 strokes but high compression. oil mix is 100:1

Most of these bikes can handle the cheapest low octane pump gas with little or no pefromance problems, some are oil injected so an oil that is designed for injections is nessary (for the 2 strokes of course)

I have numerous outdoor power equiptment that I use what ever fuel I have laying around (obviously not mix in a 4 stroke)

Bottom line is I treat any and all fuel I use or store reguardless of where it is used. I prefer Startron as years ago I WAS sponsored by them, but after the sponsorship was up I still continued to buy and use the stuff.

 

[CompactTractorFan]

This thread has seemed to wonder off a little, so getting back on track...

We used to use regular gas (mixed with oil) for all our 2-stroke engines. We purchased an Echo leaf blower last Fall, and the dealer recommended using high octane fuel, so we switched to that for all the 2-stroke stuff. We still use regular gas for all our 4-stroke small engines.

No fuel problems yet either way...

 

[jonyyuma]

If you still have doubts about Ethanol fuel..then slide over to read at Yamaha outboards web site. They have a Great section on ethanol fiuel and its bad natures to boats?? Myself I am glad they haven't upped our fuel above 10 % ethanol. I can still find plain gasoline in a few stations..

 

[Bird]

The manuals for my Toro ZTR and its 15 hp Kohler Courage engine call for 87 octane "or higher". A fuel stabilizer/conditioner is also recommended. Ethanol up to 10% is approved, but no other alcohol blend or more than 10% ethanol are approved. As I've mentioned earlier in this thread, I used the mid-grade (89 octane) with Stabil and Stihl HP Ultra 2 cycle oil in my 2 cycle engines. I use the same gasoline with Stabil, but without 2 cycle oil in the Toro.

 

[joshuabardwell]

If you still have doubts about Ethanol fuel..then slide over to read at Yamaha outboards web site. They have a Great section on ethanol fiuel and its bad natures to boats?? Myself I am glad they haven't upped our fuel above 10 % ethanol. I can still find plain gasoline in a few stations..

Having lost two carburetors to ethanol before I learned my lesson, you don't have to convince me. I use Sta-bil in all my 2-stroke engines, and bleed all my 4-stroke, non-fuel-injected engines dry using the fuel cutoff when I'm done using them.

 

[Tollster]

Get the highest octane you can get, the premium will last the longest and give you the most effecient use on a two stroke engine

Keep your pre mix out of the sun, and tightly sealed. Ethenol is a hygroscopic,therefore it will attract moisture, not goodfor any engine,this is one of the reasons you want premium,it sours less quickly,has less ethenol, and gives your two stroke the most perfomance.

 

[mjonesnh]

No way in heck its 12 to 1 in a turbo or any usual car.

Have 2012 Ford Focus with 2.0 direct fuel injection. Compression is 12.0:1

 

[Richard]

We have a friend that is a pro arborist. Real tree doctor, not just trimmer.

His take is, these little motors are 10,000+ rpm machines; run them on good premium and a high quality mix. They are, like little race motors.

I agree with this.

Put it this way...... how expensive is it really, to fill your 2 or 5 gallon tank with premium?

I used to have a Maico 490 dirt bike. I would drive an hour away to get aviation fuel at a small airport to use it instead of pump gas for the car. I could tell a noticable difference in the pulling power of the engine and the "blubbering" that regular gas could cause it to do.

I figured since I was already getting the good stuff, I'd use it in all my 2-stroke engines and used it for my chainsaw and string trimmer. They might use fuel, but they don't use THAT much fuel.

Today, I don't have the bike anymore but I'm still retentive on using as high octane as I can find.

2-strokes love octane

 

[scrappy isb67]

No way in heck its 12 to 1 in a turbo or any usual car.

I was off a little bit, i looked again and found 10.3 spec for compression ratio. But my point is that just because an engine is turbocharged does not mean it has lower compression ratio.

"The cooling effect of directly injecting fuel into the combustion chamber lets VW get away with a high-for a turbocharged engine-compression ratio of 10.3:1."
2006 Jetta 2.0 turbo

and you can also somewhat limit detonation by timing the injector pulse to just prior to ignition. you can't have detonation without fuel present
Back on subject, I have run ethanol ALL my life and NEVER had any issues. In my current small gas engines I use premium because that is what the chainsaw needs it. one less can and less confusion! as it is I have 3 cans, a 2stroke gas, a 4stroke gas, and a diesel.

 

[joshuabardwell]

Put it this way...... how expensive is it really, to fill your 2 or 5 gallon tank with premium?

Maybe sixty cents a gallon more expensive? If regular is $3 a gallon, sixty cents is 20%. So every sixth time you fill up your tank, it could be free. How many tanks do you go through in a season? The real question is, are you spending that 20% extra on something other than peace of mind. If peace of mind is worth 20% to you, that's your prerogative.

I figured since I was already getting the good stuff, I'd use it in all my 2-stroke engines and used it for my chainsaw and string trimmer. They might use fuel, but they don't use THAT much fuel.

If the convenience of not having to keep up with another fuel can is worth 20% to you, that's your prerogative too!

2-strokes love octane

Why? The whole point of octane is to resist pre-detonation, right? If the engine is not designed to take advantage of high octane gas, I can't see what advantage putting high octane in is going to give you. I keep asking this question, and people just keep kind of saying, "high-octane good!" without really responding to the question.

this is one of the reasons you want premium,it sours less quickly,has less ethenol

No disrespect, but every source I can find says that E10 gasoline has 10% ethanol by volume, regardless of grade. Do you know different?

 

[JoeBuyer]

I use 89 octane ethanol free gas. I started the 89 octane because I also read my Stihl manual and just use it across the board. There is only 1 ethanol free local station at the farm store but it really isn't that much more expensive, maybe 10 cents a gal.

 

[Tollster]

People will continue to tell you that and with some continual research you will find that 2 stroke engines where developed to run on high test gasoline. They do not have valves and burn fuel on every stroke, I actually run aviation fuel in all my saws. The only engines I know of that do not make the most of premium fuel are those less than 10:5:1 compression, unless it is a turbo model.



I actually have to look hard in my area,but with a web search of non e10 premium gas on google I got quite a few hits.


Here are some good threads to read up on,then follow up with the husky ethanol challenge,you may win something there.

Ethanol Free Premium Coalition

Husqvarna: Take the Ethanol Challenge!


I too like Richard Raced and rode dirt bikes for 40 years and learned a lot about 2 strokes, (Not including my Kawasaki 3 cylinder 2 stroke H2 roadbike) I also ran avation fuel, Cam2,and powermist in my racing machines on race day, I recall doing a little test for my own budget back than. With regular high test,I could grab 4 gears in 50 yards,but when I ran the Av gas,it was 6 gears in fifty yards. Now in this day and age and the rising issues thay have with ethanol deterating carb seals, breakdown of premix,combined with the water absorption, I personally have made it a point to do what is best for my engines,as well as take less effort of of my aging body and buy the highest octane I can find in my local area.
I am sure you will be able to skate by with lesser quality fuel, how long I don't know,as I refuse to do that test,but a quick google of "ethanol and two strokes" simply tells me there aremore troubles with it than not.
Don;t sweat the respect thing, we are all about helping one another out, thats the reason you post questions here,and this subject will have many a various answer. I just wanted to share with you what I have learned in 40 years of two strokes,and never loosing one,and I aim to keep it that way.