Honda gx 690 and a generac gth 990 here. I would like to see actual myth-buster type tests I guess. I understand the concept but, if it's not knocking, is there then nothing to be gained by increasing the octane? Running at constant speed and load, does that matter? I'm inclined to take the testimony of long time users.
Is there a benefit to using high octane in small engines? Theoretical benefit? Actual experienced benefit?
More learning,
[h=2]Read Your Owner’s Manual[/h]Unless your engine is knocking, buying higher octane gasoline is a waste of money. Premium gas costs 15 to 20 cents per gallon more than regular. That can add up to $100 or more a year in extra costs. Studies indicate that altogether, drivers may be spending hundreds of millions of dollars each year for higher octane gas than they need.
It may seem like buying higher octane “premium” gas is like giving your car a treat, or boosting its performance. But take note: the recommended gasoline for most cars is regular octane. In fact, in most cases, using a higher octane gasoline than your owner's manual recommends offers absolutely no benefit. It won't make your car perform better, go faster, get better mileage, or run cleaner. Your best bet: listen to your owner's manual.
The only time you might need to switch to a higher octane level is if your car engine knocks when you use the recommended fuel. This happens to a small percentage of cars.
From the FTC.
http://www.consumer.ftc.gov/articles/0210-paying-premium-high-octane-gasoline
Knocking is generally caused by engine tolerances going out of spec, either on rods, bearings, valves, etc. Not by fuel type unless drastically different, 86o vs 114o You put 114 in a small engine it will likely run very hot, melting parts, would knock as soon as springs for the valves heated up and stretch out.
Tom, you need to read your spark plug. I'm sure there is info on U Tube and the net. Start there, then worry about octane, hotter plugs, and more that relates to a performance engine than a small engine. Oh ya the engine in my dragster is basically a 511, it runs on race fuel, for mine I run 120 octane, she get in the 7s at 170 mph. I used to run down at SIR down in you area, nice track. Hope this helps or gets you a start.
Never heard of it, sounds like snake oil........ If it runs like a champ and I'm sure there a few hours on it then leave it alone and go make more money with the Honda.