
                                                                       EXHIBIT 8



                                           July 21, 1998



General Motors Acceptance Corporation
3031 West Grand Boulevard
P.O. Box 33123
Detroit, MI  48232

Dear Sirs:

In connection  with the General Motors  Acceptance  Corporation  (the "Company")
Prospectus for the proposed issue and sale of Medium-Term  Notes Due Nine Months
to Thirty Years from Date of Issue (the "Notes"), I have acted as tax counsel to
the Company,  and in that  capacity  have  furnished  certain  opinions to it. I
hereby  confirm to you that the opinion as set forth  under the heading  "United
States Federal Taxation" in the Prospectus  covering such Notes which is part of
the  registration  statement to which this letter is attached as an exhibit.  As
indicated in the opinion, the discussion sets forth a general summary of certain
United States Federal income tax  consequences  of the ownership and disposition
of the Notes as applied to original holders purchasing Notes at the issue price.
Holders  are  advised  to  consult  their own tax  advisors  with  regard to the
application of the income tax laws to their particular situations as well as any
tax  consequences  arising  under the laws of any state,  local or  foreign  tax
jurisdiction.

I hereby consent to the filing with the  Securities  and Exchange  Commission of
this opinion as an exhibit to the Registration Statement, as amended, and to the
reference to tax counsel under the heading  "United States Federal  Taxation" in
the  Prospectus.  By providing  the foregoing  consent,  I do not admit that tax
counsel  fall within the  category of persons  whose  consent is required  under
section 7 of the Securities Act of 1933, as amended.


                                           Yours very truly,

                                           s/ Robert N. Deitz
                                           ------------------
                                           Robert N. Deitz
                                           Senior Tax Counsel
