Cal. Rev. & Tax. Code § 7312

“Entry” means the importing of motor vehicle fuel into this state. However, motor vehicle fuel brought into this state in the fuel tank of a motor vehicle or aircraft shall not be deemed to be an “entry” if not removed from the fuel tank except as used for the operation of that motor vehicle or aircraft, except to the extent that the motor vehicle fuel was acquired tax free for export or a refund of tax was claimed as a result of exportation from the state from which that motor vehicle fuel was transported into this state.