Dan, barring any external abuse I would expect at least 5 years and with care and cleaning more than that. I have a set of 8MM Sprio Pro wires on my own vehicle that I purchased from a Western Auto store in '91 and they still function without a problem and look nice enough to show. Thanks for the inquiry.
Thank you for choosing Taylor,
Mike Birch
Taylor Cable Products, Inc.
Customer Service Representative
800-821-3600
info@taylorvertex.com