Exhibit 8.1

Santander Drive Auto Receivables LLC

1601 Elm Street, Suite 800

Dallas, Texas 75201

Ladies and Gentlemen:

We have acted as special tax counsel to Santander Drive Auto Receivables LLC (the “Seller”) and Santander Consumer USA Inc. (“SC”) in connection with the above-captioned Registration Statement (the “Registration Statement”) and the offering of the Class A-1 Auto Loan Asset Backed Notes, the Class A-2 Auto Loan Asset Backed Notes, the Class A-3 Auto Loan Asset Backed Notes, the Class B Auto Loan Asset Backed Notes, the Class C Auto Loan Asset Backed Notes and the Class D Auto Loan Asset Backed Notes (collectively, the “Notes”) described in the final prospectus dated August 13, 2018 (the “Prospectus”), which has been filed with the Securities and Exchange Commission pursuant to Rule 424(b) under the Securities Act of 1933, as amended (the “Act”). As described in the Prospectus, the Notes will be issued by Santander Drive Auto Receivables Trust 2018-4 (the “Issuer”), a trust formed by the Seller pursuant to a trust agreement (as amended, restated or otherwise modified, the “Trust Agreement”) between the Seller and Wilmington Trust, National Association, as owner trustee. The Notes will be issued pursuant to an Indenture (the “Indenture”) between the Issuer and Wells Fargo Bank, National Association, as indenture trustee (the “Indenture Trustee”).

In that connection, we generally are familiar with the proceedings required to be taken in connection with the proposed authorization and issuance of the Notes and have examined copies of such documents, corporate records and other instruments as we have deemed necessary or appropriate for the purpose of this opinion, including the Prospectus, the Trust Agreement and the Indenture (including the form of the Notes included as an exhibit thereto) and other documents prepared in connection with the issuance of the Notes (collectively, the “Operative Documents”).

Mayer Brown LLP operates in combination with other Mayer Brown entities, which have offices in North America,

Europe and Asia and are associated with Tauil & Chequer Advogados, a Brazilian law partnership.

MAYER BROWN LLP

Santander Drive Auto Receivables LLC

August 15, 2018

Page 2

The opinion set forth herein is based upon the applicable provisions of the Internal Revenue Code of 1986, as amended (the “Code”), Treasury regulations promulgated and proposed thereunder, current positions of the Internal Revenue Service (the “IRS”) contained in published Revenue Rulings and Revenue Procedures, current administrative positions of the IRS and existing judicial decisions. No tax rulings will be sought from the IRS with respect to any of the matters discussed herein. The statutory provisions, regulations and interpretations on which our opinions are based are subject to change, which changes could apply retroactively. In addition, there can be no assurance that positions contrary to those stated in our opinions may not be taken by the IRS.

Based on the foregoing and assuming that the Operative Documents are executed and delivered in substantially the form we have examined and that the transactions contemplated to occur under the Operative Documents in fact occur in accordance with the terms thereof, we are of the opinion that the statements, to the extent that they constitute matters of law or legal conclusions with respect thereto relating to United States federal income tax matters, set forth in the Prospectus under the headings “Summary of Terms—Tax Status” and “Material Federal Income Tax Consequences”, which statements have been prepared by us, are correct in all material respects, and, to the extent such statements expressly state our opinions or state that our opinion has been or will be provided as to the Notes, we hereby confirm and adopt the opinions set forth therein.

MAYER BROWN LLP

Santander Drive Auto Receivables LLC

August 15, 2018

Page 3

We know that we are referred to under the captions referred to above included in the Prospectus, and we hereby consent to the use of our name therein and to use of this opinion for filing of this opinion as Exhibit 8.1 to a Form 8-K filed in connection therewith, without admitting that we are “experts” within the meaning of the Act or the rules and regulations of the Securities and Exchange Commission issued thereunder, with respect to any part of the Registration Statement or the Prospectus.