A lot of users are falsely reporting the N1 is too low. The truth is that the N1 is accurate and completely follows the charts from the FCOMs.
The rated N1 is affected by this three factors,
- Pressure Altitude
- OAT - Outside Air Temperature
- Airspeed of the aircraft
On a Cold day, with a low Pressure altitude, a TOGA N1 can be as low as 85.1%.
On a hot day, with high pressure altitude, a TOGA N1 can be as high as 91.2%.
So, do not be alarmed if you see such low N1, if you think you cant make if off that runway, check your payload/fuel and Flap setting.