701—18.38 (422,423) Urban transit systems. A privately owned urban transit system which is not an instrumentality of federal, state or county government is subject to sales tax on fuel purchases which are within the urban transit systems charter.
Tax shall not apply to fuel purchases, made by a privately owned urban transit company, for use outside the urban transit system charter in which a fuel tax has been imposed and paid and no refund has been or will be allowed.
Whether an urban transit company will be considered an instrumentality of federal, state or county government for the purpose of receiving sales tax exemption on its fuel purchases, which are also exempted from fuel tax and used for public purposes, depends upon consideration of the following:
	  1. 	 Whether it is created by government.
	  2. 	 Whether it is wholly owned by government.
	  3. 	 Whether it is operated for profit.
	  4. 	 Whether it is primarily engaged in the performance of some essential governmental function.
	  5. 	 Whether the payment of tax will impose an economic burden upon the corporation, or that payment of tax serves to materially impair the usefulness or efficiency of the corporation or the payment of tax materially restricts the corporation in the performance of its duties.
These above enumerated considerations are not all inclusive and the presence of some and absence of others does not necessarily establish the exemption. Unemployment compensation of North Carolina v.	Wachovia Bank and Trust Company, 2 S.E.2d 592, 595, 215 No.	Car. 491 (1939); 1976 O.A.G. 823, 827, 828.
This rule is intended to implement Iowa Code subsection 422.45(1).