Over many years i have used almost every string trimmer available,and what has come out of that is my employees are given echoes to use and i use my stihls mmmmm
Regular is $1.36/litre here and you need premium because of that Ethanol crap... So the 4mix being better on fuel will be nice. The dealers all say Stihl here
Dealers here say run from still. Fuel efficiency between still 4mix and standard echo or shindaiwa 2 cycle is nominal and the shindaiwa t254 is more fuel efficient and much more reliable.