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30% Off Online Orders of Select Parts and Accessories. Enter Promo Code PEP30 in Cart

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30% Off Online Orders of Select Parts and Accessories
Receive 30% Off Your Online Purchase. Use promotional code PEP30 at checkout to receive discount. Not valid in combination with any other discounts or promotions. Not valid on gift cards, special orders, installed merchandise, commercial or fleet purchases. Excludes the following categories: Tires, Wheels, Batteries, Powerstop Brake Kits, Oil, Antifreeze, Refrigerant, Truck Boxes, Vent Visors, Bug Shields and BRANDS: Razor, Traxxas, Superchips, Hypertech, Edge, Bully Dog, Diablo, Edelbrock, Holley, NOS, Proform, Specialty Auto, Thule, Autometer, Accel, K&N, Kenwood, Pioneer, Sony, JVC, MSD and BBK Performance. Valid online until 2:59 am EST on 10/27/16. Online orders scheduled for in-store pick up must be completed by closing on 10/26/16 for discount to apply.

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  • Part #: MM12R|
  • SKU: 118712

Available today

Pay in Store Available

    • Helps improve fuel economy
    • Cleans and lubricates fuel injectors and carburetors
PayPal available for online purchases. Major credit cards accepted online and in store. Pay online, in-store or take advantage of our Pep Boys credit card. Learn more and see additional details in cart.

Marvel Mystery Oil Oil and Fuel Additive

Since 1923, Marvel Mystery Oil has helped increase the life of countless engines of all types. Marvel Mystery Oil cleans the engine from the inside out while increasing fuel economy and protecting against temperature extremes. Regularly use Marvel Mystery Oil in your oil and fuel to enhance overall performance.
  • Helps improve fuel economy
  • Cleans and lubricates fuel injectors and carburetors
  • Reduces and prevents varnish and gum build up
  • When added to oil, prevents valve sticking and clatter
  • When added to oil, prevents oil breakdown caused by extreme temperatures
  • This item must be picked up in the store as it may contain materials which are flammable or corrosive.


Rated 4.7 out of 5 by 47 reviewers.
Rated 5 out of 5 by Great Product Really cleans engine, my 12 year old car runs better October 8, 2016
Rated 5 out of 5 by Works as advertized I have known of this product for years. I even sold it to people when I worked in a parts store during my college years. I recently tried it on a high mileage SUV. I am now a believer. September 10, 2016
Rated 5 out of 5 by Very good product, excellent additive for any engine. I have used this product before and it functions well in any engine I pour it into. I believe what it states on the label and will use it again. September 1, 2016
Rated 5 out of 5 by It is almost winter Used Marvel Mystery Oil for more than 50 years. I was introduced to it by my father. It was used in every fuel powered system used by the company he worked for. It was critical to fuel systems in use during the winter months. October 11, 2016
Rated 5 out of 5 by myster oil Have used this product for years. It always does the job. A friend saw me using it and was surprised it was still available. Told him to go to Pep Boys on the Concord Pike, and he could buy it there. August 23, 2016
Rated 5 out of 5 by Awesome product I love this product! It works wonders for my truck August 22, 2016
Rated 5 out of 5 by Works great My engine is quiter and more throttle responsive August 11, 2016
Rated 5 out of 5 by Good additive for fuel I've been using this product for years with older cars that are driving on original injectors this product has proved to maintain as well as when I began, clean injectors in my 1995 and 2000 vehicles. August 10, 2016
  • 2016-10-20 T08:42:28.754-05:00
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