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, 2018 (the "2018 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 2018 Consolidated Financial Statements are attached as Exhibit 99.1 to Suncor's annual report on Form 40-F for the year ended December 31, 2018 (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 2018 Annual Information Form (the "2018 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, 2018, which is attached as Exhibit 99.2 to the Form 40-F (the "2018 Management's Discussion and Analysis").

The reserves data presented herein, with an effective date of December 31, 2018, 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 2018 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 2018 Consolidated Financial Statements, the 2018 Management's Discussion and Analysis and the 2018 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)	SCO (mmbbls)				Bitumen (mmbbls)				Crude Oil⁽³⁾ (mmbbls)				Natural Gas (bcf)				Total (mmboe)
	2018		2017		2018		2017		2018		2017		2018		2017		2018		2017
Proved Developed
Oil Sands		2 183		2 205		1 003		117		—		—		—		—		3 186		2 322
Exploration and Production		—		—		—		—		91		96		1		6		91		97

		2 183		2 205		1 003		117		91		96		1		6		3 277		2 419

Proved Undeveloped
Oil Sands		522		533		602		1 522		—		—		—		—		1 123		2 055
Exploration and Production		—		—		—		—		67		45		10		—		69		45

		522		533		602		1 522		67		45		10		—		1 193		2 100

Proved
Oil Sands		2 704		2 737		1 605		1 640		—		—		—		—		4 309		4 377
Exploration and Production		—		—		—		—		158		140		11		6		160		141

		2 704		2 737		1 605		1 640		158		140		11		6		4 469		4 519

(net reserves, constant prices and costs)

Oil Sands
SCO (mmbbls)	3 040	(143	)	—	—	—	(160	)	—	2 737
Bitumen (mmbbls)	533	1 108		—	39	—	(40	)	—	1 640
Exploration and Production
Crude oil⁽³⁾ (mmbbls)	115	64		—	—	1	(40	)	—	140
Natural gas (bcf)	11	3		—	—	—	(7	)	—	6

Total (mmboe)	3 690	1 029		—	39	1	(240	)	—	4 519

(net reserves, constant prices and costs)

Oil Sands
SCO (mmbbls)	2 737	52	—	71	—	(156	)	—		2 704
Bitumen (mmbbls)	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

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, 2018									At December 31, 2017

($ millions)	Oil Sands			Exploration and Production			Total			Oil Sands			Exploration and Production			Total
Exploration and evaluation assets⁽¹⁾		2 100			219			2 319			1 896			156			2 052
Oil and gas properties⁽²⁾		17 083			20 763			37 846			16 244			19 965			36 209
Plant and equipment⁽²⁾		63 213			1 104			64 317			63 381			1 042			64 423
— accumulated provision⁽²⁾		(22 654	)		(14 075	)		(36 729	)		(22 664	)		(12 990	)		(35 654	)

Total		59 742			8 011			67 753			58 857			8 173			67 032

(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 16 of the 2018 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 2018 Consolidated Financial Statements.

Costs Incurred for Property Acquisition, Exploration and Development Activities

	Year ended December 31, 2018						Year ended December 31, 2017

($ 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		335		—		335
Exploration⁽¹⁾		73		179		252		19		97		116
Development⁽²⁾		3 398		800		4 198		4 505		604		5 109

Total		4 614		1 093		5 707		4 859		701		5 560

(1): Includes amounts capitalized to Exploration and Evaluation as well as those charged to Exploration Expense on the Consolidated Balance Sheets and the Consolidated Statements of Comprehensive Income, respectively, of the 2018 Consolidated Financial Statements.
(2): Includes amounts capitalized to Property, Plant and Equipment on the Consolidated Balance Sheets of the 2018 Consolidated Financial Statements that relate to the company's decommissioning and restoration activities.

	Year ended December 31, 2018									Year ended December 31, 2017⁽¹⁾

($ millions)	Oil Sands			Exploration and Production			Total			Oil Sands			Exploration and Production			Total
Operating revenues, net of royalties		15 345			3 217			18 562			12 919			2 911			15 830
Other income (loss)		288			(71	)		217			86			(14	)		72

		15 633			3 146			18 779			13 005			2 897			15 902
Purchases of crude oil and products		1 563			—			1 563			623			—			623
Operating, selling and general		7 570			503			8 073			6 257			422			6 679
Transportation		1 144			85			1 229			827			86			913
Depreciation, depletion, amortization and impairment		4 024			967			4 991			3 782			1 028			4 810
Exploration		44			78			122			15			89			104
(Gain) loss on disposal of assets		(108	)		91			(17	)		(50	)		—			(50	)
Finance expenses		320			46			366			180			36			216

Earnings (loss) before income taxes		1 076			1 376			2 452			1 371			1 236			2 607
Income taxes — expense (recovery)		223			568			791			362			504			866

Net earnings (loss)		853			808			1 661			1 009			732			1 741

(1): On January 1, 2018, the company adopted IFRS 15 Revenue from Contracts with Customers using the retrospective method. In accordance with the new standard, the company assessed the principal versus agent requirements and the impact was a decrease in revenue, with a corresponding decrease to Operating, Selling and General expense and Transportation expense, resulting in no impact on the company's consolidated net earnings. As a result prior period information has been restated. See note 5 of the 2018 Consolidated Financial Statements.

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, and adjusted for decommissioning and restoration activities and 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
2018		71.54		65.56		50.44		70.07		79.39		1.46		10.03
2017		54.07		51.03		51.09		63.43		67.46		2.35		8.45

	At December 31, 2018									At December 31, 2017

($ millions)	Oil Sands			Exploration and Production			Total			Oil Sands			Exploration and Production			Total
Future cash inflows		247 927			14 259			262 186			203 625			9 229			212 854
Future production costs		(132 241	)		(3 446	)		(135 687	)		(108 045	)		(3 508	)		(111 553	)
Future development costs		(56 071	)		(3 175	)		(59 246	)		(49 554	)		(2 574	)		(52 128	)
Future income tax expenses		(14 491	)		(1 988	)		(16 479	)		(11 074	)		(945	)		(12 019	)

Future net cash flows		45 124			5 650			50 774			34 952			2 202			37 154
10% Discount Factor		(23 280	)		(1 227	)		(24 507	)		(15 209	)		(114	)		(15 323	)

Standardized measure of discounted future net cash flows		21 844			4 423			26 267			19 743			2 088			21 831

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	21 831		7 780
Sales and transfers of oil and gas produced	(6 998	)	(4 618	)
Net change in sales prices and operating costs related to future production	6 277		18 461
Net change due to extensions, discoveries and improved recovery	3 923		2 804
Net change due to acquisitions and dispositions	1 228		—
Net change due to revisions in quantity estimates	1 630		(1 695	)
Previously estimated development costs incurred during the period	3 805		2 742
Changes in estimated future development costs	(6 010	)	(36	)
Accretion of discount	2 210		657
Net change in income taxes	(1 629	)	(4 264	)

Standardized measure of discounted future net cash flows — end of year	26 267		21 831