It depends on the state of charge of your Model X. The less charge you come in with, the faster it will charge. The more charge you have, the slower it will charge. Also the emptier the Supercharger is, the faster it will charge.
It depends on your batery size too. Do you have a 75D aka standard range or 100D aka long range. Overall It doesn't matter. Follow car's instructions. Just charge enough to reach the next point.
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