The award-winning STIHL four-stroke engine that runs on a petrol-oil mix. The STIHL 4-MIX engine thus combines the advantages of a 2-stroke and a 4-stroke.

Which STIHL trimmers are 4-mix?

• FS 91 / FS 91 R.
• FS 111 / FS 111 R / FS 111 RX.
• FS 131 / FS 131 R.
• BR 500 / BR 600 / BR 700 / BR 800 C-E / BR 800 X.

Is STIHL FS 91 A 4-stroke?

It also bears mentioning that, while the Stihl FS 91 R does feature a 4-stroke engine, it still requires premix fuel.