I flashed my stock car with stage 1 95oct and I was very happy , big smile, car was great. As I am using European 98RON fuel , which would be equivalent to US 93oct, I tested stage 1 93oct too and my opinion is the power difference huge. So I can imagine how low power 91oct map might feel. Btw the 95oct map seem to fit my car with 98RON EU fuel. Regardless the advice that I should use US 93oct, logs looks similar, few corrections on both maps. No error codes, So am sticking with 95oct map as the EU 98RON in Western Europe seem to match more US 95oct than 93oct. I did also a test with stage 1+ 93 oct , and even that feels weeker than stage 1 95oct map, The only big advantage I noticed, I get aprox. 15% more miles with 93oct map and the car feels very smooth in any gear, but less sportive.