The calculated distance (air line) between Ciudad Nezahualcoyotl and San Miguel de Allende is approximately 153 miles respectively 247 kilometers.
By car or train, the actual journey to San Miguel de Allende is certainly longer, as only the direct route (as the crow flies) between Ciudad Nezahualcoyotl and San Miguel de Allende has been calculated here.
Air line (approximately)
247 kilometers
133 nautical miles