Really you probably wont notice any power difference when dropping down from 30% to say 15 % nitro content with this large Saito 100. if it was a small 21 sized engine this would be a totally different story as the small engines love a higher nitro content compared to the larger sizes. i went through this stage with many r/c power boat engines and picked up australian speed records in the process , even some of the best U.S. racers commented on the not so good effects with high nitro on larger engines . most model aircraft engines are not designed to run high nitro especially the 4 strokes as head clearance and dome sizes are there to stay stock. when going to a higher nitro content its not just a matter of richening up the main needle and fitting a different heat range plug , you must raise the head dome by fitting correct sized shims which means the engine will have less compression compared to stock but will handle the nitro plus plugs wont get destroyed .