Additive Kits

Doc's Diesel Additive Kits

Don't Buy a Bottle. Buy a Plan.

Single additives solve single problems. Diesel engines don't have single problems—they have a fuel system, an oil system, and an emissions system all aging at once. Doc's Additive Kits bundle treatments that work together into complete protection strategies, so instead of guessing which bottle to grab, you run a plan: daily protection in every tank, periodic deep cleaning on schedule, and engine-side defense where wear actually happens.

Pick the Strategy That Fits Your Truck.

The 1-2 Punch pairs every-tank 24/7 Diesel Treatment with concentrated Interval cleaning—the classic fuel system defense. The Long-Haul Protection Kit teams 24/7 with Oil Friction Treatment for owners keeping their truck forever. The Clean & Protect Bundle combines deep fuel cleaning with engine wear protection. The Workhorse Kit runs all three—fuel protection, fuel cleaning, and oil treatment—for trucks that earn their name. And the DEF System Kit pairs high-purity DEF with DEF Guard to keep emissions systems crystal-free and derate-free.

Proven Formulas. Kit Pricing.

Every treatment in every kit is the same third-party-tested, warranty-safe formula sold individually—bundled at better value, with clear dosing on every bottle. No mystery juice, no miracle claims. No guesswork. No BS.

Doc's Makes It Easy.

Match the kit to how your truck lives: daily driver or fleet truck, run the 1-2 Punch; high-mileage or heavy towing, step up to Long-Haul or the Workhorse; emissions-equipped, add the DEF System Kit. Every product page spells out exact dosing and frequency.

Free Shipping on All U.S. Orders $99+

A kit typically clears the free shipping line on its own—everything over $99 ships free anywhere in the U.S. Don't buy a bottle. Buy a plan.