SUNCOR ENERGY INC

Reserves Data

Reserves data 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 — Advisories – Reserves Data” section in Suncor’s 2024 Annual Information Form (the “2024 AIF”), which is attached as Exhibit 99.1 to the Form 40-F. Readers should also see Suncor’s Management’s Discussion and Analysis for the year ended December 31, 2024, which is attached as Exhibit 99.3 to the Form 40-F (the “2024 Management’s Discussion and Analysis”).

The reserves data presented herein, with an effective date of December 31, 2024, 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 2024 AIF. SEC 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. In 2024, Suncor’s reserves were economic utilizing both constant pricing permitted by SEC, as well as forecast pricing permitted by NI 51-101.