Octane?

[catflyer]

My brother told me I should only run 89 or higher in my mower. He says that he never uses regular (87) in his small engines or mowers. Is this your advice as well? Thanks, Brian

[cgaengineer]

Sounds good to me. Its cheap. Higher octane does not yield higher performance from a normally aspirated engine...especially a lawn mower engine. So unless your mower engine is running 12:1 compression and Wiseco pistons and rods 87 octane will be just fine.

[catflyer]

Thanks! I put regular in the last time and am glad to know I'm not harming it.

[ksJoe]

Avoiding ethanol/alcohol is good if you can. It absorbs moisture worse than straight gasoline. It doesn't matter in a car where you're using it quickly, but in your mower gas that sits for months its more likely to cause problems (like rusting needle valves in the carb).

I always put stabil in all my mower & edger gas to keep it fresh. Its about $10 at Walmart for enough to treat 80 gallons.

[catflyer]

Thanks Joe, my brother already has me doing that. I think I might start buying it at Walmart though. Much cheaper than my beloved local hardware store.

[STIHL GUY]

i run 87 in my mower and 93 octane for all my mixed gas

[topsites]

I run premium in everything. :waving:

[Shasta Lake Landscaping]

cgaengineer has it right..

[HighFiveBassin]

As a homeowner too I always buy premium. It's not that it is any better (or worse) for my equipment but because gasoline begins to lose octane very quickly and unlike the commercial guys it may take me up to a couple of months to run through my gas. I also use Stabil but no additive prevents octane loss. I can really tell when my gas is getting stale as my Stihl trimmer and blower begins to run like crap. I put in fresh gas and they immediately run great.