Heavy-Duty Ceramic Engine Protection Built for Class 7 & Class 8 Semi Trucks

Typical factory oil fill capacities for common Class 8 engines: Cummins X15 / ISX ≈ 12–13 gallons (OEM spec is 44–50 quarts depending on sump); Detroit DD13 ≈ 11–12 gallons; Detroit DD15 ≈ 12–13 gallons (standard sump) / 14 gallons (extended); Detroit DD16 ≈ 13–14 gallons; Paccar MX-13 ≈ 12–13 gallons; Volvo D13 / D16 ≈ 11–14 gallons; Caterpillar C15 ≈ 11–12 gallons; Mack MP7 / MP8 ≈ 10–13 gallons. Always confirm with the capacity plate on your specific engine or your OEM service manual — sump sizes vary by spec. Round up rather than down to ensure you have enough to complete the change. Extra gallons can be kept for between-change top-off (important with 30K-mile drain intervals).

Both Cermax viscosities offered in this package are formulated to meet API CK-4 heavy-duty diesel performance requirements. 15W-40 is the traditional heavy-duty linehaul viscosity — broad temperature tolerance, heavier film strength under sustained load, and preferred by most fleets running older engines and mixed-climate routes. 10W-30 provides modest fuel-economy gain (typically 0.5–1.5% in controlled fleet testing) and meaningful cold-start protection benefits in northern winter operation. Modern Cummins X15, Detroit DD15/DD16, and Paccar MX-13 are factory-spec-approved for 10W-30 under the OEM's extended oil drain program. Some newer engines are additionally approved for FA-4 low-HTHS formulations for further fuel economy gains — if your engine specifically requires FA-4 only (not CK-4), contact us at 239-344-9861 before ordering to confirm current stock. When in doubt, 15W-40 is the safer choice across the widest range of Class 7/8 applications.

Under the Magnuson-Moss Warranty Act (US federal law), an OEM cannot void your engine warranty simply because you used an aftermarket product — they must demonstrate that the specific product caused a specific failure. Cerma STM-3 and Cermax oil are EPA ETV certified, CK-4 formulated (for the oil), and contain no prohibited additives. That said, maintaining a clean warranty claim requires discipline: keep records of every oil change (date, mileage, product used), retain used oil analysis (UOA) reports if you run extended drains, and use Cermax at the viscosity approved by your OEM for your engine. Every major OEM (Cummins, Detroit, Paccar, Cat) publishes extended oil drain guidelines that depend on UOA — follow those, document them, and your warranty position is strong. For fleet-scale questions or specific warranty situations, call us at 239-344-9861 before ordering.

Run the math on your own numbers, but here's a typical Class 8 scenario. A tractor running 125,000 miles/year on a 25,000-mile drain schedule does 5 oil changes per year. At 13 gallons CK-4 synthetic ($90–100/gal at bulk rate) + filter ($45) + labor ($125) = roughly $1,400/change × 5 = $7,000/year. On a 30,000-mile drain with Cermax (confirmed safe via UOA), the same tractor does ~4.2 changes/year at roughly the same per-change cost = $5,880/year. The per-mile difference is small but compounds across a fleet, and the larger value sits in less downtime (one fewer service bay visit per tractor per year) and in the wear-reduction side of the equation — lower oil consumption, reduced blow-by progression, and slower bearing-clearance drift across the engine's life. For owner-operators, the downtime gain alone often justifies the package.

UOA is the right way to set a drain schedule for any fleet operation. If your UOA reports (TBN, soot, fuel dilution, viscosity index, wear metals — Fe, Cu, Pb, Al, Cr) come back within OEM-approved ranges at 30K, many operators extend to 35K, 40K, or 45K+ on Cermax under favorable conditions (linehaul duty cycle, high engine hours per mile, moderate climate). The Cerma-treated engine typically shows lower wear-metal counts than an untreated engine on the same oil, which gives you more headroom on the drain interval. Our recommendation: start at 30K, run UOA at 30K, 35K, and 40K across your first few tractors, and let the data set your fleet-wide interval. For severe-service, mountain, or vocational applications (heavy PTO use, short-haul with frequent start-stop, very hot climates), stay at 25–30K until UOA confirms margin to extend.

Yes, as long as your underlying transmission fluid is an Allison- or Eaton-approved product. The Cerma Transmission Treatment is added to your existing fluid — it does not replace OEM-spec fluid. For an Allison 3000/4000/4500 automatic, keep running your TES-295- or TES-389-approved ATF (TranSynd, Castrol TranSynd 668, or equivalent) and add the 6 oz treatment once. For an Eaton Fuller manual or AMT, keep running PS-164 rev 7 synthetic (Roadranger, Mobil Delvac Synthetic Transmission Fluid, or equivalent) and add the 6 oz treatment once. The SiC ceramic bonds to the transmission's internal metal surfaces over the first 1,500–3,000 miles of normal operation — the OEM-approved fluid continues to carry heat and provide its normal lubrication chemistry. This is how we keep the warranty framework intact.

High-mileage trucks are often where Cerma shows the most driver-perceivable change, because these engines have the most accumulated wear and the most friction-generated heat to reduce. What to realistically expect: smoother idle, modestly improved fuel economy (typically 1–3% on a stable linehaul duty cycle), reduced oil consumption between changes, less blow-by pressure in the crankcase, and lower observed operating temperature. What not to expect: Cerma will not restore compression that has already been lost to scored cylinder liners, broken piston rings, or damaged bearings — those are mechanical failures that require repair. If your engine is healthy but aging, the full protocol can meaningfully extend remaining service life. If it's already showing mechanical distress (blue smoke under load, coolant in oil, rapid oil pressure loss), diagnose and address the underlying issue before treating.

Honest answer: the biggest, most reliable effects of a full Cerma protocol on a Class 8 diesel are reduced wear progression and extended oil-change intervals. Those are the two claims we stand behind without qualification. Secondary effects — fuel economy gains, temperature reduction, blow-by reduction, smoother idle — are real and reported consistently by operators, but they vary significantly by engine condition, duty cycle, driver behavior, route, and load. Typical observed fuel economy improvement on a stable linehaul operation after full protocol completion is 1–3% (for a tractor doing 7.0 MPG, that's 7.07–7.21 MPG). Compression: Cerma cannot restore compression lost to mechanical damage, but on engines with normal wear, the ceramic layer can reduce cylinder-wall leakdown readings meaningfully by sealing micro-imperfections. We'd rather set accurate expectations up front than have you disappointed after 30 days — the real win is wear-reduction economics over 300K–500K additional service miles, not a single-digit MPG number on this week's dispatch.