With all the hubbub down below about how a/f curves are not the only parameter of tuning a car, you can't seriously think that AFC tuning is a full tune of the car, can you? What about the other huuuuge factor - timing? What does the AFC do for that? In a word - nothing. Additionally, how does AFC tuning account for variable engine load/boost pressure? It doesn't. Your AFC settings and corresponding A/F curve are good for a single set of conditions, and are not correct for the rest of the engine's range of operating conditions. Tuning controls the fuel maps for the entire range of engine operating conditions, as well as adjusting timing to increase power and prevent detonation. AFC tuning can't do all of that.