High octane gas in JD mower????

franchi

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Hello All:

I put 93 octane gasoline in my JD LT 110 to see if there was any difference in the way that it would run. WOW! What an improvement! It appeared to start faster and run much smoother with more power than the 86 octane that I had been using. Perhaps I was just fooling myself. At an additional 33 cents more a gallon, I am curious if it is worth the extra expense.

Thoughts/comments

Tia,

Franchi
 

7394

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100% gas is what works for me.

Here's the story. Ethanol contains about 80,000 btu's of energy. Gasoline contains 118,000 btu's of energy. Contrary to popular belief, higher octane does not equate to more power or more energy contained in a gallon of gas. Octane inhibits gasolines ability to burn. Higher octane gas is better suited for higher compression engines prone to detonation.
Since ethanol contains less energy per gallon, you have to add more gas to do the same amount of work. Bottom line, if you burn gas with no ethanol, you will see 5-8% better fuel economy (less gas burned to do the same amount of work) and about a 3-5% increase in horsepower. Yes, gas with ethanol is usually cheaper in most parts of the country. This is because ethanol is subsidised by the government and costs less per gallon. This encourages stations to purchase it because they can sell their gas for less. In some states and locals, it is mandated, usually at 10%. Use gas without ethanol and you will feel the difference and get better gas mileage. If you put a pencil to it, you will get enough of an increase in fuel economy to pay the difference in the cost.
 

MowLife

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I always thought mower engines were tuned for 87 from the factory....but may be wrong. If a mower is properly tuned then higher octane fuel will add performance. You would need to advance your timing.
 

7394

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They are tuned for 87 unless your owners manual states otherwise.

No mower running the stock tune has optimum power or economy regardless of whats in the tank.
 

ILENGINE

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I run 93 octane in all my equipment and my vehicles. It started with my supposedly tuned for 87 octane 96 Dakota that sounds like the rods are coming out of it if you use anything less than 89. Stihl, Makita/Dolmar, Husqvarna call for a minimum octane rating of 90-91 in their equipment per the owners manual so it is easily to just purchase 93 octane.
 

Black Bart

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100% gas is what works for me.

Here's the story. Ethanol contains about 80,000 btu's of energy. Gasoline contains 118,000 btu's of energy. Contrary to popular belief, higher octane does not equate to more power or more energy contained in a gallon of gas. Octane inhibits gasolines ability to burn. Higher octane gas is better suited for higher compression engines prone to detonation.
Since ethanol contains less energy per gallon, you have to add more gas to do the same amount of work. Bottom line, if you burn gas with no ethanol, you will see 5-8% better fuel economy (less gas burned to do the same amount of work) and about a 3-5% increase in horsepower. Yes, gas with ethanol is usually cheaper in most parts of the country. This is because ethanol is subsidised by the government and costs less per gallon. This encourages stations to purchase it because they can sell their gas for less. In some states and locals, it is mandated, usually at 10%. Use gas without ethanol and you will feel the difference and get better gas mileage. If you put a pencil to it, you will get enough of an increase in fuel economy to pay the difference in the cost.

Putting 93 in a mower is like throwing beefsteak to the hogs. A total waste.
 

mechanic mark

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I agree ILENGINE, vehicles & outdoor power equipment, i also use fuel treatment in outdoor power equipment. JOHN DEERE recommends fuel treatment when you visit "GREEN PARTS STORE" for your model tractor. Notice ILENGINE'S credentials, certifications, etc.
 

cpurvis

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High octane fuel has less BTU's than lower octane because it weighs less per gallon.
 

jp1961

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Hello,

Here's my .02 cents. Higher octane gas is needed in higher compression (> 10:1) engines to prevent piston knock. It's actually less explosive than regular. Running it in a 8.5:1 engine is a waste of money IMO.

Regards

Jeff
 
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