Fuel for Stihl equipment.

[JRR]

Stihl recommends 89 octane, or higher, gasoline for their equipment.

I was purchasing a new Stihl KM 130 R KombiMotor trimmer the other day, (it cuts heavy grass almost as well as my very old 4-cycle Ryobi 1079r ... but that's another story!) and the salesman was very persistent that I know to purchase 89 or higher octane gasoline for its use.  I thought this was because of the "4-cycle" X-Mix engine used on that particular trimmer .... but later, looking back thru their catalogue I see high octane gasoline is recommend for all current equipment.

On the page listing all the Stihl mix oils, there is this note: STIHL recommends a mix of 50:1 high-quality 89 octane or higher unleaded gasoline to STIHL engine oil.  This same mix ratio should be used during break-in.

When did this come about?  I've been asleep at the switch if it applies to my older Stihl equipment.  I've been using 87 octane regular non-leaded.

Heads up!

[peternap]

There's a lot of debate about that. One argument is that high test has less alcohol...I don't know but I burn high test alcohol free gas in all my small engines and I have very few problems.

[NM_Shooter]

I also believe that at higher altitudes you can burn the lower octane.  Less air density, less chance for detonation.