Exhibit 12.2

PETROLEOS MEXICANOS SUBSIDIARY ENTITIES AND SUBSIDIARY COMPANIES

Computation of ratio of earnings to fixed charges

	June
	2007
	(in thousands of
	Mexican pesos
	as of December			June 2008
	31, 2007			(in thousands
	purchasing			of Mexican
	power)			pesos)
Mexican Financial Reporting Standards
Fixed Charges(1):
Interest capitalized in fixed assets		4,103,036			1,940,302
Interest expense		27,363,768			30,386,481
Total interest cost		31,466,804			32,326,783
Total Fixed Charges		31,466,804			32,326,783
Net income		21,865,460			39,389,131
Hydrocarbon Income Tax (IRP)		2,541,759			1,904,441
Income Tax and Others		2,537,704			4,490,137
Cumulative effect of adoption of new accounting standards		—			—
Profit sharing in subsidiaries and affiliates (income from equity investees)		(8,076,723	)		(4,356,570	)
Minority Interest		12,529			(64,110	)
Pretax income from continuing operations before income from equity investees		18,880,729			41,363,029
Fixed Charges(1):		31,466,804			32,326,783
Amortization of interest capitalized		164,121			77,612
Distribution of income of investment shares		—			—
Interest capitalized in fixed assets		(4,103,036	)		(1,940,302	)
Earnings		46,408,618			71,827,122
Amount by which fixed charges exceed earnings		(14,941,814	)		(39,500,339	)
Ratio of earnings to fixed charges		1.4748			2.2219

(1) These figures do not include rental expense