I was wondering in those test that were performed what percent of nitro was used in the engines. You see satios like high nitro and run considerably better with it. Go check out the review of the new Satio 100 verses the OS .91 at Horizon. You will notice that the satio keeps on making power as the nitro is increased beyond 20% were the OS really does not have a change. This leaves me to believe the OS has a high compression ratio than the satio which would seem to be the reason they run better on lower nitro fuel. I would like to see a comparison with the Satio .91 using 30% heli verses the OS .91 Surpass using 30%. I believe the results would come out more in favor of the satio here. An by the way Horizon recommends the use of 30% heli in satios.