The following disclosures are presented in accordance with United States Financial Accounting Standards Board ("FASB") Topic 932 — "Extractive Activities — Oil and Gas" and Subpart 1200 of Regulation S-K ("Subpart 1200") of the United States Securities and Exchange Commission. Disclosures pertaining to the audited consolidated financial statements as at and for the year ended December 31, 2019 (the "2019 Consolidated Financial Statements") of Suncor Energy Inc. ("Suncor" or the "company") were prepared in accordance with International Financial Reporting Standards as issued by the International Accounting Standards Board and Canadian generally accepted accounting principles contained within Part 1 of the Chartered Professional Accountants Canada Handbook, which differ in material respects from financial statements prepared in accordance with United States generally accepted accounting principles. The 2019 Consolidated Financial Statements are attached as Exhibit 99.1 to Suncor's annual report on Form 40-F for the year ended December 31, 2019 (the "Form 40-F").

Reserves data included herein are estimates only and can be significantly impacted by a variety of internal and external factors. For more information on the risks involved when estimating reserves, see the discussion in the "Statement of Reserves Data and Other Oil and Gas Information — Significant Risk Factors and Uncertainties Affecting Reserves" section in Suncor's 2019 Annual Information Form (the "2019 AIF"), which is contained in the Form 40-F. Readers should also see Suncor's Management's Discussion and Analysis for the year ended December 31, 2019, which is attached as Exhibit 99.2 to the Form 40-F (the "2019 Management's Discussion and Analysis").

The reserves data presented herein, with an effective date of December 31, 2019, may differ in relation to the format and the basis from which volumes are economically determined under National Instrument 51-101 — "Standards of Disclosure for Oil and Gas Activities" ("NI 51-101"), as disclosed in the 2019 AIF. Subpart 1200 requires disclosure of net proved reserves, after royalties, using the average of the first-day-of-the-month prices for the twelve-month period prior to the end of the reporting period, whereas NI 51-101 requires disclosure of gross and net reserves, estimated using forecast prices and costs.

The majority of Suncor's oil and gas reserves are in Canada. In order to align with the company's segmented information in the 2019 Consolidated Financial Statements, the 2019 Management's Discussion and Analysis and the 2019 AIF, the company presents the following supplementary oil and gas disclosures by showing amounts associated with its Oil Sands segment, which are exclusively in Canada and produce synthetic crude oil ("SCO") and bitumen, separate from other Canadian operations, which are aggregated with Suncor's international operations (collectively, "Exploration and Production") and produce crude oil, natural gas and natural gas liquids ("NGLs"). Exploration and Production reserves are in offshore Canada, offshore UK, and offshore Norway.

	SCO (mmbbls)				Bitumen (mmbbls)				Crude Oil⁽³⁾ (mmbbls)				Natural Gas (bcf)				Total (mmboe)

At December 31, (net reserves, constant prices and costs)	2019		2018		2019		2018		2019		2018		2019		2018		2019		2018
Proved Developed
Oil Sands		2,032		2,183		951		1,003		—		—		—		—		2,984		3,186
Exploration and Production		—		—		—		—		110		91		1		1		111		91

		2,032		2,183		951		1,003		110		91		1		1		3,094		3,277

Proved Undeveloped
Oil Sands		542		522		581		602		—		—		—		—		1,123		1,123
Exploration and Production		—		—		—		—		49		67		9		10		51		69

		542		522		581		602		49		67		9		10		1,173		1,193

Proved
Oil Sands		2,574		2,704		1,532		1,605		—		—		—		—		4,106		4,309
Exploration and Production		—		—		—		—		160		158		11		11		161		160

		2,574		2,704		1,532		1,605		160		158		11		11		4,267		4,469

(net reserves, constant prices and costs)

Oil Sands
SCO (mmbbls)	2,737	52	—	71		(156	)	—		2,704
Bitumen	1,640	12	—	18		(65	)	—		1,605
Exploration and Production										—
Crude oil⁽³⁾ (mmbbls)	140	16	—	7	27	(33	)	—		158
Natural gas (bcf)	6	1	—	10	—	(3	)	(3	)	11

Total (mmboe)	4,519	80	—	98	28	(254	)	(1	)	4,469

(net reserves, constant prices and costs)

Oil Sands
SCO (mmbbls)	2,704	33		—	—	—	(164	)	—	2,574
Bitumen	1,605	(6	)	2	—	—	(68	)	—	1,532
Exploration and Production
Crude oil⁽³⁾ (mmbbls)	158	30		1	—	5	(35	)	—	160
Natural gas (bcf)	11	1		—	—	1	(2	)	—	11

Total (mmboe)	4,469	57		2	—	5	(267	)	—	4,267

Notes to Reserves Data:

(1)

Definitions

a.: Net reserves, in relation to Suncor's production and reserves, represents the company's working interest share after deduction of royalty obligations, plus the company's royalty interests in production and reserves.
b.: Proved oil and gas reserves are those quantities of oil and gas, which, by analysis of geoscience and engineering data, can be estimated with reasonable certainty (at least a 90% probability that the quantities actually recovered will equal or exceed the estimate) to be economically producible, from a given date forward, from known reservoirs, and under existing economic conditions, operating methods and government regulations.
c.: Proved developed oil and gas reserves are those quantities that can be expected to be recovered through existing wells with existing equipment and operating methods or in which the cost of the required equipment is relatively minor compared to the cost of a new well; and can be expected to be recovered through extraction equipment and infrastructure installed and operational at the time of the reserves estimate for projects that extract oil and gas by means not involving a well.
d.: Proved undeveloped oil and gas reserves are those quantities that are expected to be recovered from new wells on undrilled acreage, or from existing wells where a relatively major expenditure is required for recompletion.

(2): Reserve data tables may not add due to rounding.
(3): Natural gas liquids reserves are not significant and have been presented in combination with crude oil reserves.
(4): Revisions of previous estimates include changes to proved reserves, resulting from new information (except for an increase in proved acreage) normally obtained from development drilling and production history or resulting from a change in economic factors, such as changes in constant prices used for the reserve evaluation.
(5): Extensions and discoveries are additions to proved reserves from proved acreage of previously discovered reservoirs through additional drilling in periods subsequent to discovery or discovery of new fields with proved reserves or of new reservoirs of proved reserves in old fields.
(6): Dispositions are reductions in reserves estimates as a result of selling all or a portion of an interest in oil and gas properties. During 2018, the company disposed of its northeast B.C. mineral landholdings, including associated production.

	At December 31, 2019									At December 31, 2018

($ millions)	Oil Sands			Exploration and Production			Total			Oil Sands			Exploration and Production			Total
Exploration and evaluation assets⁽¹⁾		2,178			250			2,428			2,100			219			2,319
Oil and gas properties⁽²⁾⁽³⁾		18,795			21,801			40,596			17,083			20,763			37,846
Plant and equipment⁽²⁾⁽³⁾		66,451			1,074			67,525			63,213			1,104			64,317
— accumulated provision⁽²⁾		(30,581	)		(15,298	)		(45,879	)		(22,654	)		(14,075	)		(36,729	)

Total		56,843			7,827			64,670			59,742			8,011			67,753

(1): Exploration and evaluation assets largely represent amounts associated with unproved properties, but may include properties with proved reserves for which Suncor's Board of Directors have not sanctioned development. See note 17 of the 2019 Consolidated Financial Statements.
(2): Oil and Gas Properties, Plant and Equipment and the accumulated provision largely represent amounts associated with proved properties. See note 15 of the 2019 Consolidated Financial Statements. Includes amounts capitalized to Property, Plant and Equipment on the Consolidated Balance Sheets of the 2019 Consolidated Financial Statements that relate to the company's right-of-use assets under IFRS 16. See note 16 of the 2019 Consolidated Financial Statements.
(3): Includes amounts capitalized to Property, Plant and Equipment on the Consolidated Balance Sheets of the 2019 Consolidated Financial Statements that relate to the company's decommissioning and restoration activities.

Costs Incurred for Property Acquisition, Exploration and Development Activities

	Year ended December 31, 2019						Year ended December 31, 2018

($ millions)	Oil Sands		Exploration and Production		Total		Oil Sands		Exploration and Production		Total
Unproved property acquisition		—		—		—		—		32		32
Proved property acquisition		—		—		—		1,143		82		1,225
Exploration⁽¹⁾		204		248		452		73		179		252
Development⁽²⁾		3,580		992		4,572		3,398		800		4,198

Total		3,784		1,240		5,024		4,614		1,093		5,707

(1): Includes amounts capitalized to Exploration and Evaluation on the Consolidated Balance Sheets as well as those charged to Exploration Expense on the Consolidated Statements of Comprehensive Income, of the 2019 Consolidated Financial Statements.
(2): Includes amounts capitalized to Property, Plant and Equipment on the Consolidated Balance Sheets of the 2019 Consolidated Financial Statements that relate to the company's decommissioning and restoration activities.

	Year ended December 31, 2019									Year ended December 31, 2018

($ millions)	Oil Sands			Exploration and Production			Total			Oil Sands			Exploration and Production			Total
Operating revenues, net of royalties		17,430			3,070			20,500			15,345			3,217			18,562
Other income (loss)		172			430			602			387			(68	)		319

		17,602			3,500			21,102			15,732			3,149			18,881
Purchases of crude oil and products		1,407			—			1,407			1,563			—			1,563
Operating, selling and general		8,027			525			8,552			7,577			507			8,084
Transportation		1,293			80			1,373			1,144			85			1,229
Depreciation, depletion, amortization and impairment		8,170			1,505			9,675			4,024			967			4,991
Exploration		127			129			256			44			78			122
(Gain) loss on disposal of assets		(14	)		(228	)		(242	)		(108	)		91			(17	)
Finance expenses		318			73			391			320			46			366

(Loss) earnings before income taxes		(1,726	)		1,416			(310	)		1,168			1,375			2,543
Income taxes — (recovery) expense		(1,299	)		411			(888	)		223			568			791

Net (loss) earnings		(427	)		1,005			578			945			807			1,752

(1): Beginning in 2019, results from the company's Energy Trading business are included within each of the respective operating business segments to which the respective trading activity relates. The Energy Trading business was previously reported within the Corporate, Energy Trading and Eliminations segment. Prior periods have been restated to reflect this change.
(2): The company adopted IFRS 16 on January 1, 2019 using the modified retrospective transition approach and, therefore, prior periods have not been restated. See note 5 of the 2019 Consolidated Financial Statements for further information.

Standardized Measure of Discounted Future Net Cash Flows Relating to Proved Oil and Gas Reserves

The standardized measure of discounted future net cash flows relating to Suncor's proved oil and gas reserves are calculated in accordance with FASB Topic 932 — "Extractive Activities — Oil and Gas". Future cash inflows are estimated using the trailing twelve-month average price, which are also used in estimating the entity's proved oil and gas reserves. Future development and production costs, including the associated decommissioning and restoration activities, are calculated by estimating the expenditures to be incurred in developing and producing the proved oil and gas reserves at the end of the year, based on year-end costs and assuming continuation of existing economic conditions. The appropriate year-end statutory tax rates, with consideration of future tax rates already legislated, were applied to the future pretax net cash flows, less the tax basis of the properties involved. A prescribed rate of 10% is applied to discount the future net cash flows.

The calculation of the standardized measure of discounted future net cash flows is based upon information prepared by the company's independent qualified reserves evaluators (which includes decommissioning and restoration activities), and adjusted for future income taxes.

It should not be assumed that the estimates of future net cash flows presented in the tables below represent the fair market value of the reserves. There is no assurance that the price and cost assumptions will be attained and variances could be material. Future changes to income tax, royalty and environmental regulations could also have a significant impact on the respective assumptions. There is no guarantee that the estimates for SCO, bitumen, crude oil, and natural gas reserves provided herein will be recovered. Actual SCO, bitumen, crude oil, and natural gas reserves may be greater than or less than the estimates provided herein.

The following twelve-month average prices were used to calculate the standardized measure of discounted future net cash flows:

Year	Brent North Sea		WTI Cushing Oklahoma		WCS Hardisty Alberta		Light Sweet Edmonton Alberta		Pentanes Plus Edmonton Alberta		AECO Gas		National Balancing Point North Sea

	US$/bbl		US$/bbl		Cdn$/bbl		Cdn$/bbl		Cdn$/bbl		Cdn$/mmbtu		Cdn$/mmbtu
2019		63.15		55.69		57.22		67.66		68.70		1.66		6.69
2018		71.54		65.56		50.44		70.07		79.39		1.46		10.03

	At December 31, 2019									At December 31, 2018

($ millions)	Oil Sands			Exploration and Production			Total			Oil Sands			Exploration and Production			Total
Future cash inflows		251,040			13,218			264,258			247,927			14,259			262,186
Future production costs		(145,374	)		(3,960	)		(149,334	)		(132,241	)		(3,446	)		(135,687	)
Future development costs		(52,917	)		(3,287	)		(56,204	)		(56,071	)		(3,175	)		(59,246	)
Future income tax expenses		(10,716	)		(1,764	)		(12,480	)		(14,491	)		(1,988	)		(16,479	)

Future net cash flows		42,033			4,207			46,240			45,124			5,650			50,774
10% Discount Factor		(22,655	)		(308	)		(22,963	)		(23,280	)		(1,227	)		(24,507	)

Standardized measure of discounted future net cash flows		19,378			3,899			23,277			21,844			4,423			26,267

Changes in Standardized Measure of Discounted Future Net Cash Flows Relating to Proved Oil and Gas Reserves

($ millions)

Standardized measure of discounted future net cash flows — beginning of year	26,267		21,831
Sales and transfers of oil and gas produced	(8,005	)	(6,998	)
Net changes in sales prices and operating costs related to future production	(5,673	)	6,277
Net change due to extensions, discoveries and improved recovery	2,632		3,923
Net change due to acquisition and dispositions	—		1,228
Net change due to revisions in quantity estimates	(834	)	1,630
Previously estimated development costs incurred during the period	4,077		3,805
Changes in estimated future development costs	(314	)	(6,010	)
Accretion of discount	2,773		2,210
Net change in income taxes	2,353		(1,629	)

Standardized measure of discounted future net cash flows — end of year	23,277		26,267