While I was flying with 10+ year Airbus 320, IAE engine with EPR, I saw a constant difference between N1 parameters around 2%. I checked the Engine Hours and Engine Cycles that they are almost the same. Oil consumption of a greater N1 valued engine was less than the other one.

So why N1 parameters different? is it a sign of an engine part problem?

Note: 2% value difference at cruise level, on the ground it is around 1%

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    $\begingroup$ Can you match the N1s by splitting the thrust levers? And what are the N2 or EPR values? Are they equal while the N1s are different? $\endgroup$ – John K Nov 17 '19 at 20:54
  • $\begingroup$ Good question that could be extended to "how much thrust, temperature, N2, EPR differences are acceptable for a 2 jet engine aircraft?" $\endgroup$ – Manu H Nov 18 '19 at 9:46
  • $\begingroup$ What does your mechanic says? Sure airline like yours will have maintenance guys on hand to answer this. $\endgroup$ – vasin1987 Nov 18 '19 at 11:47
  • $\begingroup$ @JohnK EPR values were the same N2 differences were less than 1%. Generally, I did observe N2 differences for older engines less than 1% but no difference at N1 values. If it is helpful around 20 degrees Celsius difference at EGTs from take-off till landing. $\endgroup$ – denizhanedeer Nov 24 '19 at 13:24
  • $\begingroup$ @vasin1987 I asked the to our base mechanic about the difference they said they do also monitored the difference from engine performance logs but they could not give a clear answer due to the engines are at the same cycle and hours which I suspected in the first place. $\endgroup$ – denizhanedeer Nov 24 '19 at 13:26

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