Once set properly the 1.6 is very good on fuel, a couple of clicks more rich ,and the tank empties quicker..
I also can fly 10+ minutes with a bunch left (stock tank) in an EF Yak 54.
The OS 1.6 runs strong on 5-15% cheaper fuel.

YS out pulls most engines in displacement, but wants a minimum of 20% fuel and can be a bit trickier in tuning. The sound is very exotic and powerful though. They are $$
The OS 160 can fly a wide range of larger aircraft.

I think its still the best value between glow and gas (26-30cc) engines
A Bisson or Slimline pitts muffler is usually used, and many use the VP-30 pump for ultra reliable no sag performance.