
5.	INVENTORIES

Inventories consisted of the following (in millions):



	December 31,
	2018		2017
Refinery feedstocks	$	2,292	$	2,427
Refined petroleum products and blendstocks	3,678		3,459
Ethanol feedstocks and products	298		242
Materials and supplies	264		256
Inventories	$	6,532	$	6,384

As of December 31, 2018 and 2017, the replacement cost (market value) of LIFO inventories exceeded their LIFO carrying amounts by $1.5 billion and $3.0 billion, respectively, and our non-LIFO inventories accounted for $1.1 billion and $1.0 billion, respectively, of our total inventories.

During the year ended December 31, 2016, we recorded a change in our lower of cost or market inventory valuation reserve that resulted in a net benefit to our results of operations of $747 million.