Exhibit 99.1

Delaware City Refinery Tour

August 27, 2007

Agenda

Basics of Refining Desulfurization Hydrocracking

Delaware City Refinery Operations Gasification Overview Q&A Plant Tour Concluding Remarks 2

Crude Oil Characteristics

Crudes are classified and priced by density and sulfur content Crude density is commonly measured by API gravity

· API gravity provides a relative measure of crude oil density

· The higher the API number, the lighter the crude Light crudes are easier to process Heavy crudes are more difficult to process

Crude sulfur content is measured as a percentage

· Less than 0.7% sulfur content = sweet

· Greater than 0.7% sulfur content = sour

· High sulfur crudes require additional processing to meet regulatory specs

Acid content is measured by Total Acid Number (TAN)

· Acidic crudes highly corrosive to refinery equipment

· High acid crudes are those with TAN greater than 0.7 3

Crude Oil Basics

Crude Quality by Types Estimated Quality of Reserves (2006)

4.0% SOUR Cold Lake 3.5% Cerro Negro Maya WCS 3.0% CONTENT M-100 (resid) Arab Heavy Sweet

2.5% High Acid

Arab Medium 20%

(Sweet)

Dubai Light/Medium

SULFUR Napo 2%

2.0% Mars Sour Iran Heavy Arab Light Ameriven-Hamaca 2010 13% 1.5% 66% 2000 Urals Heavy

1990 Sour

1.0% Alaskan North Slope SWEET 1980

0.5% WTI

Brent

Tapis Cabinda Bonny Light 0.0%

15 20 25 30 35 40 45 50

Source: Oil & Gas Journal, Company Information

HEAVY API GRAVITY LIGHT

Source: Industry reports
NOTE: Red line represents the average crude quality by decade (actual and projected)

Majority of global reserves are light/medium sour Most quoted benchmark prices are light sweet crudes

· WTI (West Texas Intermediate), Western Hemisphere

· Brent (North Sea Crude), Europe

Historical trend shows global crude supply becoming heavier and more sour 4

What’s in a Barrel of Crude Oil? Crude Types            Characteristics            Yields

2005 U.S.

3% > 34 API Gravity            Production Light Sweet Crude 30% < 0.7 % Sulfur (e.g. WTI, Brent, Saharan            Refinery 34% 7% Blend) 35% Demand            Gases Most Expensive 33% Gasoline RFG 50% Conventional 3% CARB 24 – 34 API Gravity Medium Sour Crude 21% Premium

> 0.7 % Sulfur

(e.g. Mars, Arab Light, 26% Arab Medium, Urals) 50% Demand

33% Distillate 50% Less Expensive            Jet Fuel Diesel Heating Oil < 24 API Gravity 1% 14% Heavy > 0.7 % Sulfur 22% 10%Fuel Oil & Heavy Sour Crude            Other (e.g. Maya, Cerro Negro, Cold 15% Demand

Lake, Western Canadian Select) 63% Source: EIA Refiner Production

Least Expensive

Refineries upgrade crude oil to higher value products 5

Basic Refining Concepts

Intermediates            Final Products < 90°F            Propane, Butane • Refinery fuel gas and lighter • Propane

· NGLs 90–220°F Straight Run More

Gasoline (low • Gasoline (high octane) octane) processing

Crude oil

220–315°F            More • Gasoline (high octane) Naphtha Distillationprocessing• Jet fuel Tower (Crude• Kerosene Unit) 315–450°F            More • Jet fuel Kerosene processing • Diesel Fuel oil More • Gasoline (high octane) 450–650°F            Light Gas Oil Furnace• Diesel processing Fuel oil More • Gasoline (high octane) 650–800°F            Heavy Gas Oil • Diesel Vacuum            processing • Fuel oil Unit

· Gasoline (high octane) 800+°F Residual Fuel More • Diesel Oil/Asphalt • Fuel oil processing

Lube stocks 6

Hydroskimming/Topping Refinery

Crude Unit

Propane/Butane 4% Propane/ Butane Gasoline

Low Octane Gasoline Reformer High Octane Gasoline RFG Towerand Naphtha 30% Conventional CARB Hydrogen Premium Light            Distillation HS Kerosene/Jet Fuel Distillate

LS Kerosene/Jet Fuel

Sweet Desulfurizer 34% Distillate Crude            Jet Fuel Diesel

HS Diesel/Heating Oil LS Diesel/Heating Oil

Heating Oil Vacuum            Gas Oil Heavy

32% Fuel Oil & Unit Other

Heavy Fuel Oil

100% Total Yield

Simple, low upgrading capability refineries run sweet crude 7

Crude and Vacuum Towers

Reactor

Heater Crude Atmospheric Tower            Vacuum Tower            Reformer 8

Medium Conversion: Catalytic Cracking

Crude Unit Propane/ Propane/Butane 8%Butane Gasoline Reformer RFG Low Octane Gasoline            High Octane Gasoline 45% Conventional and Naphtha CARB Tower Premium Hydrogen Distillate

Light Distillation HS Kerosene/Jet Fuel LS Kerosene/Jet Fuel

Desulfurizer 27% Distillate Sour            Jet Fuel HS Diesel/Heating Oil            LS Diesel/Heating Oil Diesel Crude            Heating Oil

Light Cycle Oil

(LCO)

Alkylation
Unit Alkylate

Fluid Catalytic Vacuum Gas Oil

Cracker

Unit (FCC) FCC Gasoline

Heavy 24% Fuel Oil & Other

Heavy Fuel Oil

104% Total Yield

Moderate upgrading capability refineries tend to run more sour crudes while achieving increased higher value product yields and volume gain 9

High Conversion: Coking/Resid Destruction

Crude Hydrogen Plant Gas Unit Propane/ Propane/Butane 7%Butane Gasoline RFG TowerLow Octane Gasoline ReformerHigh Octane Gasoline 58% Conventional and Naphtha CARB Premium Medium/ Distillation Hydrogen Heavy Distillate 28% Distillate

HS Kerosene/Jet Fuel LS Kerosene/Jet Fuel

Sour Desulfurizer Jet Fuel Diesel Crude HS Diesel/Heating Oil            LS Diesel/Heating Oil Heating Oil

Hydrocracker Hydrocrackate Gasoline Light Gas Oil Ultra Low Sulfur Jet/Diesel LCO Alkylation

Unit Alky Gasoline

Fluid Catalytic

Medium Gas Oil Cracker (FCC)

Vacuum

FCC Gasoline

Unit Heavy 15% Fuel Oil & Delayed            Other

Heavy Fuel Oil            Coke

Coker

108% Total Yield

Complex refineries can run heavier and more sour crudes while achieving the highest light product yields and volume gain 10

FCC and Hydrocracker Reactors

Fluidized Catalytic Cracker

Reactor Hydrocracker Reactors

Main Column Regenerator 11

Cokers

Delayed Coker

Superstructure holds the drill and drill stem

Fluid Coker — Benicia while the coke is forming in the drum 12

Conversion Economics

U.S. Gulf Coast Refinery Margins

30 25 20 15

l / B b $ 10 S U

5 0 (5)

(10)

Jan-00 Jan-01 Jan-02 Jan-03 Jan-04 Jan-05 Jan-06 Jan-07

Arab Medium Hydroskimming            LLS Cracking            Maya Coking

Need conversion capacity to capitalize on sour crude discounts

· Hydroskim – Breakeven or moderate margins; High resid yield When margins are positive – increase crude runs When margins are negative – decrease crude runs

· Cracking – Better margins; Lower resid yield

· Coking – Best margins; Lowest resid yield Maximize heavy crudes 13

Desulfurization Basics

Objective

Remove sulfur from light products (gasoline or diesel) to meet air quality requirements for clean burning fuels

Desulfurization Unit

HC Desulfurized Light Products High Sulfur HC-S H2 HC-S

Light            HC-S H2 Products            H2 Elemental Catalyst (HC-S) Sulfur Plant            Sulfur

HC-S            HC-S • Agricultural H2S            S            S Pharmaceutical H2HC-S            S S            S 2 ^H Hydrogen Unit H2 LEGEND LEGEND H            H2 2 HC : HC : Hydrocarbon Hydrocarbon H2 1000 or less PSI; H2 : Hydrogen H2 H2 H2 : Hydrogen

700 F or less

SS :: Sulfur Sulfur 14

Hydrocracking Basics

Objective

Value added upgrading of high sulfur distillates to low sulfur gasoline and ultra low sulfur jet/diesel to meet air quality requirements for clean burning fuels

Hydrocracking Unit HC Desulfurized Hydrocrackate Gasoline High Sulfur HC-S H2 HC-S

HC-S H2

Distillate H2 H HC Desulfurized Ultra Low Sulfur Jet/Diesel

2 (HC-S) H2 Catalysts H2 Elemental H2 HC-S H2 HC-S            Sulfur PlantSulfur

H2 • Agricultural H2 H2S            S            S S• Pharmaceutical HC-S            S

2 S            S ^H Hydrogen Unit H2 LEGEND LEGEND H2 H2 HC : HC : Hydrocarbon Hydrocarbon H2 1300+ PSI; H : Hydrogen H2 H2 H 2 : Hydrogen 725 to 780 F 2

SS :: Sulfur Sulfur 15

Andrew Kenner

Vice President and General Manager Delaware City Refinery 16

Valero Delaware City Refinery

Built by Tidewater Oil Company in 1957 Acquired by Valero in 2005 Since commissioning, Valero and previous owners have made significant modifications and environmental upgrades Total throughput of 191,000 bpd High conversion operation

· 60%+ gasoline yield

Staffed by more than 700 full-time employees Located on 5,000 acres, some of which is leased to local farmers, preserving our buffer zone Seeking OSHA VPP Star Status 17

Delaware City Products and Crude Slate

Typical Product Slate Typical Crude Slate

Product BPD % Crude S % / API BPD %

Gasoline 85,000 50 Arab Heavy 2.7 / 29 75,000 45 Distillates 65,000 38 M-100 2.7 / 16 45,000 26 Propane 7,500 4 Hamaca 1.6 / 26 35,000 20 Alkylate 5,000 3 Opportunity Crudes 15,000 9 6 Oils 4,500 3 Total 170,000 100 Benzene 1,500 1 Pet coke 1,900 1 Sulfur 300 < 1 Total 170,700 100

Provides approximately 70% of all gasoline sold in Delaware Flexible light-ends system Produces petrochemical grade Benzene for sales into local market. 18

Delaware City Capital Investments

$456 MM invested in capital improvements and $97 MM for turnaround maintenance at Delaware City since Valero’s acquisition

· Major plant turnaround completed in 4Q05 Fluid Coker Flue Gas Scrubber — $200 MM

Fluid Catalytic Cracking Unit Flue Gas Scrubber — $200 MM

Cracked Naphtha Hydrotreating Unit expansion project commissioned in 4Q05 Sulfur Plant O2 enrichment and reliability projects — $25 MM

Took over operations of Gasifier/Power Plant and have improved on-stream reliability and throughput dramatically

Petcoke Destruction (TPD) 1,100 650 300 Motiva            Premcor            Valero 19

Gasification Overview

File: GASIF03.vsd by: MEL 5/15/98

Delaware City Plant Air Separation

Coke Gasification Repowering Project Plant Gas Turbine            Electric Power Oxygen Clean Syngas

To Refinery Coke Steam To Sulfur Fluxant Water Refinery Removal Boiler To Feed Utility Raw Syngas Exhaust Gas Water Syngas Cooler Gasifier

Heat Recovery Boiler Steam Generator Feed Water Slurry High Pressure Steam Slag Acid Gas

Electric To Power Utility

To Sulfur Sulfur Refinery

Recovery Unit

Existing Steam

Steam To Turbine Refinery 20

Appendix

Delaware City Refinery Flow Diagram 22

Map of Valero Refineries

Quebec, Canada 215,000 bpd capacity Benicia, California

· 170,000 bpd capacity

Paulsboro, New Jersey 195,000 bpd capacity Delaware City, Delaware Wilmington, California • 210,000 bpd capacity

· 135,000 bpd capacity

McKee, Texas

· 170,000 bpd capacity

Memphis, Tennessee

· 195,000 bpd capacity Three Rivers, Texas

· 100,000 bpd capacity

Ardmore, Oklahoma

· 90,000 bpd capacity

Corpus Christi, Texas

Valero Marketing • 340,000 bpd capacity Krotz Springs, Louisiana

Presence • 85,000 bpd capacity St. Charles, Louisiana

· 250,000 bpd capacity

Houston, Texas

· 130,000 bpd capacity Port Arthur, Texas Texas City, Texas

· 245,000 bpd capacity • 325,000 bpd capacity San Nicholas, Aruba

· 275,000 bpd capacity Capacity shown in terms of crude and feedstock throughput 23

Major Refining Processes – Crude Processing Definition

· Separating crude oil into different hydrocarbon groups

· The most common means is through distillation

Process

· Desalting – Prior to distillation, crude oil is often desalted to remove corrosive salts as well as metals and other suspended solids.

· Atmospheric Distillation – Used to separate the desalted crude into specific hydrocarbon groups (straight run gasoline, naphtha, light gas oil, etc.) or fractions.

· Vacuum Distillation – Heavy crude residue (“bottoms”) from the atmospheric column is further separated using a lower–pressure distillation process. Means to lower the boiling points of the fractions and permit separation at lower temperatures, without decomposition and excessive coke formation. 24

Major Refining Processes – Cracking

Definition

· “Cracking” or breaking down large, heavy hydrocarbon molecules into smaller hydrocarbon molecules thru application of heat (thermal) or through the use of catalysts

Process

· Coking – Thermal non–catalytic cracking process that converts low value oils to higher value gasoline, gas oils and marketable coke. Residual fuel oil from vacuum distillation column is typical feedstock.

· Visbreaking – Thermal non–catalytic process used to convert large hydrocarbon molecules in heavy feedstocks to lighter products such as fuel gas, gasoline, naphtha and gas oil. Produces sufficient middle distillates to reduce the viscosity of the heavy feed.

· Catalytic Cracking – A central process in refining where heavy gas oil range feeds are subjected to heat in the presence of catalyst and large molecules crack into smaller molecules in the gasoline and surrounding ranges.

· Catalytic Hydrocracking – Like cracking, used to produce blending stocks for gasoline and other fuels from heavy feedstocks. Introduction of hydrogen in addition to a catalyst allows the cracking reaction to proceed at lower temperatures than in catalytic cracking, although pressures are much higher. 25

Major Refining Processes – Combination

Definition

· Linking two or more hydrocarbon molecules together to form a large molecule (e.g. converting gases to liquids) or rearranging to improve the quality of the molecule

Process

· Alkylation – Important process to upgrade light olefins to high–value gasoline components. Used to combine small molecules into large molecules to produce a higher octane product for blending with gasoline.

· Catalytic Reforming – The process whereby naphthas are changed chemically to increase their octane numbers. Octane numbers are measures of whether a gasoline will knock in an engine. The higher the octane number, the more resistance to pre or self–ignition.

· Polymerization – Process that combines smaller molecules to produce high octane blending stock.

· Isomerization – Process used to produce compounds with high octane for blending into the gasoline pool. Also used to produce isobutene, an important feedstock for alkylation. 26

Major Refining Processes – Treating

Definition

· Processing of petroleum products to remove some of the sulfur, nitrogen, heavy metals, and other impurities

Process

· Catalytic Hydrotreating, Hydroprocessing, sulfur/metals removal – Used to remove impurities (e.g. sulfur, nitrogen, oxygen and halides) from petroleum fractions. Hydrotreating further “upgrades” heavy feeds by converting olefins and diolefins to parafins, which reduces gum formation in fuels. Hydroprocessing also cracks heavier products to lighter, more saleable products. 27

List of Refining Acronyms

AGO – Atmospheric Gas Oil kVA – Kilovolt Amp ATB – Atmospheric Tower Bottoms LCO – Light Cycle Oil B–B – Butane–Butylene Fraction LGO – Light Gas Oil

BBLS – Barrels LPG – Liquefied Petroleum Gas BPD – Barrels Per Day LSD – Low Sulfur Diesel BTX – Benzene, Toluene, Xylene LSR – Light Straight Run (Gasoline) CARB – California Air Resource Board MON – Motor Octane Number CCR – Continuous Catalytic Regenerator MTBE – Methyl Tertiary–Butyl Ether DAO – De–Asphalted Oil MW – Megawatt DCS – Distributed Control Systems NGL – Natural Gas Liquids DHT – Diesel Hydrotreater ^NOX ^{– Nitrogen Oxides} DSU – Desulfurization Unit P–P – Propane–Propylene EPA – Environmental Protection Agency PSI – Pounds per Square Inch

ESP – Electrostatic Precipitator RBOB – Reformulated Blendstock for Oxygen Blending FCC – Fluid Catalytic Cracker RDS – Resid Desulfurization GDU – Gasoline Desulfurization Unit RFG – Reformulated Gasoline GHT – Gasoline Hydrotreater RON – Research Octane Number GOHT – Gas Oil Hydrotreater RVP – Reid Vapor Pressure GPM – Gallon Per Minute SMR – Steam Methane Reformer (Hydrogen Plant) HAGO – Heavy Atmospheric Gas Oil ^SOX ^{– Sulfur Oxides} HCU – Hydrocracker Unit SRU – Sulfur Recovery Unit HDS – Hydrodesulfurization TAME – Tertiary Amyl Methyl Ether HDT – Hydrotreating TAN – Total Acid Number HGO – Heavy Gas Oil ULSD – Ultra–low Sulfur Diesel HOC – Heavy Oil Cracker (FCC) VGO – Vacuum Gas Oil H2 – Hydrogen VOC – Volatile Organic Compound H2S – Hydrogen Sulfide VPP – Voluntary Protection Program HF – Hydroflouric (adic) VTB – Vacuum Tower Bottoms HVGO – Heavy Vacuum Gas Oil WTI – West Texas Intermediate kV – Kilovolt WWTP – Waste Water Treatment Plant 28

Safe Harbor Statement

Statements contained in this presentation that state the Company’s or management’s expectations or predictions of the future are forward–looking statements intended to be covered by the safe harbor provisions of the Securities Act of 1933 and the Securities Exchange Act of 1934. The words “believe,” “expect,” “should,” “estimates,” and other similar expressions identify forward–looking statements. It is important to note that actual results could differ materially from those projected in such forward– looking statements. For more information concerning factors that could cause actual results to differ from those expressed or forecasted, see Valero’s annual reports on Form 10-K and quarterly reports on Form 10-Q, filed with the Securities and Exchange Commission, and available on Valero’s website at www.valero.com.