i have a few engines and was looking at the tower hobbies magazine the difference in the description on these engines and have a few questions please:
one engine is an OS 61 FX; acording to tower ractical rpm range:2000-17000
hp@rpm 1.9@16000

the second is av super tigre 90(china version) ractical rpm range: 2500-16000
hp@rpm: 2.5@14800

well the question is: what practical rpm range means? what hp@rpm means?
what is the rule to decide wich one is more powerfull or has more torque?or has more speed?
what is the rule in this cases?
wich one is more powerfull for a cessna 182 gold edition kit from top flite; the 0s 61 fx or super tigre 90?
regards.