A bit of a spoiler right from the start. If you are after a general-purpose farm saw with a bit of extra power for some heavy work, a model such as the 64.1cc Stihl MS391 is a good ‘top end’ choice. Now take a look at the 79.2cc MS500i. Like the 391, the 500i weighs the same 6.2kg without fuel, oil, bar and chain. The former, however, develops 3.3kw/4.5hp, the 500i rating at a far brawnier 5.0kW/6.8hp. It is clear which one has the better power to weight ratio.