No matter the condition of your 2015 CTS, OPGI has the Oils, Fluids & Additives you need to boost performance and get you back on the road. We currently carry six Oils, Fluids & Additives to choose from for your 2015 CTS, and our Price Match Guaranteed prices range from as little as $10.95 up to $29.99. OPGI offers Auburn Gear plus one other trusted brands of Oils, Fluids & Additives for your 2015 CTS, to help you find quality parts you can rely on. With OPGI's 45-day return policy and thousands of customer reviews, you can shop with the utmost confidence. Enjoy parts delivered directly to your home, or visit our sunny Southern California Showroom & Warehouse to check out our Oils, Fluids & Additives in person.