The thing is, the MAX definitely has bigger legs than an 800. It will literally sip the fuel. The problem is, that the MAX is 3 tonnes heavier than an 800 with the same 26k rated engines. Of course it’s not going to perform as well in the climb. You definitely notice it on a normal climb out takes about (30mins to reach cruise) and much more so in a go around. Everything happens a lot slower.
The new engines coming on the next round are the exact same engines as the previous ones. The difference is that the chip “unlocks” the higher engine rating. In this case some will have 27k and some will have 28k.
The 700 is lighter than an 800 with 24k engines on it. So it can’t carry as many pax but still has the same wing and fuel capacity. They’re like a little sports car and very responsive. I love flying the 700.
With a higher engine rating comes more maintenance costs. We were told when the ex Silk Air aircraft got converted to 27k to only use it if operationally required and maintenance will be monitoring the use of it. That’s because it was a novelty and we wanted to feel what 27k felt like…and it was good

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