Leases

We lease ocean transport vessels, tugboats, barges, pipelines, railcars, service station sites, computers, office buildings, corporate aircraft, land and other facilities and equipment. Certain leases include escalation clauses for adjusting rental payments to reflect changes in price indices, as well as renewal options and/or options to purchase the leased property. There are no significant restrictions imposed on us by the leasing agreements with regard to dividends, asset dispositions or borrowing ability. Our capital lease obligations relate primarily to the lease of an oil terminal in the United Kingdom. The lease obligation is subject to foreign currency translation adjustments each reporting period. The total net PP&E recorded for capital leases was $231 million and $203 million at December 31, 2015 and 2014, respectively.

Future minimum lease payments as of December 31, 2015, for operating and capital lease obligations were:



	Millions of Dollars
	Capital Lease Obligations		Operating Lease Obligations

2016	$	24	510
2017	25		418
2018	19		308
2019	18		234
2020	14		171
Remaining years	169		368
Total	269		2,009
Less: income from subleases	—		99
Net minimum lease payments	$	269	1,910
Less: amount representing interest	61
Capital lease obligations	$	208

Operating lease rental expense for the years ended December 31 was:



	Millions of Dollars
	2015		2014	2013

Minimum rentals	$	641	570	572
Contingent rentals	6		8	7
Less: sublease rental income	136		135	133
	$	511	443	446