i wouldn't waste the money, especially with gas prices this high.. In a ZTR yes, maybe, but in a $300 mower no way

 

I never heard that one. Every mower I've ever used, the manual said to use regular octane.

 

Nope, I've been through a two semester course on small engine repair and both instructors said run FRESH unleded regular in the motors. The preimum stuff has addatives that are abrasive and will wear out the rings.

That being said, I always run whatever grade gasoline the owner's manual recommends in any machine I own.

 

Don't waste your money, it doesn't need it.

 

I have heard that premium is better for small engines. I use mid grade in all my equipment.

 

I was originally told and have since always used premium unleaded petrol, mainly in the Toro Z.

Even in the Honda line trimmer the premium unleaded gives a bit more power than straight unleaded crap.

 

Originally posted by tx_angler
Nope, I've been through a two semester course on small engine repair and both instructors said run FRESH unleded regular in the motors. The preimum stuff has addatives that are abrasive and will wear out the rings.

That being said, I always run whatever grade gasoline the owner's manual recommends in any machine I own.

I seriously doubt this. I have three mowers with over ten years commercial use so I think this blows that theory, in my opinion anyway.

 

the higher the octane,,,,,the COOLER the gas burns,,,,,or slower thus the no pinging!

 

Norm Al is on the money. If it doesn't ping, no need for higher octane.

 

Higher octane gas just has more additives to slow the burn like the others said. Only needed for pinging or pre-ignition (the gas/air mixture ignites during compression before the spark ignites).

You probably just needed the carb jets cleaned of some gunk that is partially blocking the fuel flow. My mower has the same problem every few years. The first time I took it to a mechanic that charged $50 to clean it. Now I know how to do it myself, very easy.

Bob

 

Where I fet my gas , the only higher octane they have is the e-10 unleaded with ethonal. (gasahol) I have heard that this is not good for small engines. I think they call it oxygenated fuel and the manual says don't use oxygenated fuels.
What is the mechanics take on this?

 

Thanks for all your replys. Kind of a hot topic based upon all the different responses.

 

Are you sure he is referring to the Octane? Because mine means premium BRAND. Gas IS gas until each manufacturer gets their hands on it. Each company: Amoco, Exxon, Shell, etc... adds their own additives and detergents; Thus changing the quality of the fuel.

Take a look the next time and see there is yellow gas and white gas (Amoco is white.) I have put yellow gas in a carburated engine and in little time had to rebuild the carb because it had PURE shellac in it. I AWAYS us white gas now. It burns much cleaner and more efficient.

 

i have had some trouble with this,only in small engines,
dealer mech said not to run ethanol, basically because it has alcohol in it and that attracts moisture to build in both the fuel can, and tank on the mower, larger engines(kohler twins) no problem with using ethanol

 

Originally posted by mowit12000
i have had some trouble with this,only in small engines,
dealer mech said not to run ethanol, basically because it has alcohol in it and that attracts moisture to build in both the fuel can, and tank on the mower, larger engines(kohler twins) no problem with using ethanol

According to a Ford fuels specialist the reason you do not want to use ethanol in a two cycle engine is that it may not mix with the two cycle oil, a very bad thing.

 

thank you, i will keep that in mind also

 

Originally posted by Heron Cove PM
Are you sure he is referring to the Octane? Because mine means premium BRAND. Gas IS gas until each manufacturer gets their hands on it. Each company: Amoco, Exxon, Shell, etc... adds their own additives and detergents; Thus changing the quality of the fuel.

Take a look the next time and see there is yellow gas and white gas (Amoco is white.) I have put yellow gas in a carburated engine and in little time had to rebuild the carb because it had PURE shellac in it. I AWAYS us white gas now. It burns much cleaner and more efficient.

Now that's interesting. I've heard the "white gas is better" bit many times and when I asked why nobody else has ever given any other answer than "it runs better in my car."

I've owned numerous different vehicles over the years and I've never had one that would run better on Amoco/BP fuel. In fact all mine ran like 'you know what' on it from every gas station in the area. Phillips 66, same deal.

I like Citgo, Hess, Shell, Texaco and Exxon gas. Never paid attention to what color those were.

 

As a long time former Amoco dealer I can give you my opinion on gasoline:

Gasoline is changed by each Brand as the additives they put in to make their own registered formulas, but the color of gas means nothing to it's worth. The only BP (Amoco) gasoline that is near white is Amoco Ultimate. And is no better than most other premium brands except BP demands more coinage for Amoco Ultimate for some unknown reason.

Most all premium blends use MTBE's as an additive to make the higher octane rating. Premiums do not burn slower than other fuels because of the additives included in the fuel. Actually quite to opposite as the higher the octane rating the more explosive. Premium fuels are some times recommended for engines in higher altitudes and can be used in hotter climates as they do allow the engine to run slightly cooler.

Ethanol based fuels are not oxygenated fuels. That's a totally different animal used in very few of the larger markets for extra pollution control mandated by federal law.

10% added ethanol fuels are recommended by every four stroke engine manufacturer as they run cleaner, keep engines running cleaner and continually clean the entire fuel system from the gas cap to the tail pipe. You will never see and water contained in fuel systems as ethanol absorbs the water and continually keeps the system pure. Never any wintertime fuel line freezing.

Though gasohol (ethanol added fuels) are not always recommended for two cycle engines, but can be run in them. The port system of the 2 cycle engines are no more effecient with ethanol based fuels.

I run ethanol fuel in everything I own from my truck and motorcycle to all my four stroke mowers. Regular unleaded in all two stroke engines.

My opinion... premium fuels are a waste of good money except in high performance engines (Porsche Turbos) and higher altitude or vehicles with heavy loads or heavy trailers.

Just my opinion.

 

I had a small engine mechanic tell me the same thing, but it was with regards to 2-cycle equipment.

 

I have read and have also been told by lawn mower mechanics that 90 and higher octane burns hotter and can cause valves to burn up much faster than if you use 89 octane which is the recommended octane on most mowers.I am not sure if this is gospel but it made sense to me and I have not used over 89 for 3 seasons and no problems yet.

 

Originally posted by Four C. Landscaping
I have read and have also been told by lawn mower mechanics that 90 and higher octane burns hotter and can cause valves to burn up much faster than if you use 89 octane which is the recommended octane on most mowers.I am not sure if this is gospel but it made sense to me and I have not used over 89 for 3 seasons and no problems yet.

I can't imagine why it would burn hotter, the higher octane causes it to burn slower, thus saving detonation which will burn a hole in your piston[now that's hot!].
I have two Honda 21's that are 10 & 12 years old and a 12.5.
Kohler with 13 years on it that have never seen anything but 91 octane. None have ever had any valve maintenance and hold good compression, I'll stick with the good stuff.

 

As I said it may not be gospel but you do not see nascar or dragsters using 91 they want a more powerful power stroke and you do not get that from a slower burn.
Or am I wrong all together.

 

Originally posted by Four C. Landscaping
As I said it may not be gospel but you do not see nascar or dragsters using 91 they want a more powerful power stroke and you do not get that from a slower burn.
Or am I wrong all together.

Isn't racing fuel like 102 or something,

 

Trust me, without getting into a LOOOOng chemistry discussion, premium fuel in your eguipment is pretty much a waste of money. I will admit though that my trimmer and blower DO run Cooler on 93. I attribute this to my local climate. The ONLY reason you would need a higher octane fuel is if you are currently into detonation, on the fuel you are currently using( like 87 ). It's so humid here and hot (right now) that I have used some 93 in my mix gas lately... Mostly to prevent vapor lock, and as I mentioned earlier it does help throttle response and keeps the 2 stroke stuff a little cooler, and truthfully, the difference is negligable. But there is no way I would waste the $$$ putting premium in my mowers.. THEY DON'T NEED IT.

 

And yes, dishboy, some race gas is as high as 118 octane... It burns SLOWER to resist detonation when you run a 16:1 compression ratio, in something like a Pro Stock drag car... Only Lawn equipment I've seen running 16:1.... Would be diesel.