120bhp Vs 165bhp
 

I've looked everywhere for an answer to this, so hoping someone is wise enough to enlighten me. The Mazda 3 has 120bhp and 165bhp versions, the engine is identical on both and the 120bhp version is simply limited by software. I am curious how the fuel economy differs between them. I have found the attached graphs (https://www.automobile-catalog.com/curve/2016/2506775/mazda_3_2_0_skyactiv-g_165_i-eloop.html) & (https://www.automobile-catalog.com/curve/2017/2506745/mazda_3_2_0_skyactiv-g_120.html) which illustrate their torque/hp curves and below 4000rpm they are identical. Does this mean that below 4000rpm the fuel economy will also be identical and a difference will only become apparent when you start exceeding 4000rpm? Or is there something else that I'm not aware of that will affect the fuel economy/performance?