KRL 20 h loss≤ 8% (CEC L-45-A-99)
FZG scuffing≥ 12 (A/8.3/90)
Low-temp viscosityBrookfield −40 °C ≤ 120k cP
Copper corrosion1a @ 3 h / 100 °C
Customer
Regional blender supplying gear oils for mobile and industrial drives; complaints on viscosity drop after service and shear-down in field.
Challenge
- Shear loss in KRL > 15% with incumbent OCP VI improver.
- Cold-crank limits near spec; foam in Seq II.
- Hold cost and keep existing additive house where possible.
Approach
Blend design around PAO-6/8 with 10–15% synthetic ester for seal/solvency, a shear-stable OCP VI improver, and balanced ZDDP + S-P EP/AW. Anti-foam trimmed to hit Seq II.
Formulation window
| Component | Function | Use level | Notes |
|---|---|---|---|
| PAO-6 / PAO-8 | Primary base oil | 70–82% | Target ISO VG via ratio. |
| Synthetic ester | Polarity/low-temp | 8–15% | TMP/POE improves VI & seals. |
| OCP VI improver (shear-stable) | Viscosity index | 5–9% | Pre-dissolve @ 110 °C. |
| ZDDP | Antiwear | 0.6–0.9% | P content per spec. |
| S-P EP package | Load/scuff | 1.5–3.0% | Match GL-4/GL-5 target. |
| Antioxidant (phenolic/amine) | Oxidation | 0.3–0.6% | Thermal stability. |
| Antifoam (silicone) | Foam control | 5–15 ppm | Tune for Seq II. |
Processing & testing
- Charge base; dissolve VI improver at 100–115 °C, recirculate ≥ 30 min.
- Cool < 60 °C; add EP/AW, AO, antifoam; polish filter.
- Test: KRL 20 h, FZG A/8.3/90, D892 foam, D130 copper, D445 viscosity, Brookfield @ −40 °C.
Results
Viscosity loss 6–8% (KRL), FZG stage 12–13, Brookfield −40 °C 90–110k cP, Seq II foam 0/0. Field trials showed stable viscosity after 1,000 h and clean gear surfaces.
Regulatory: Supplied with
SDS/COA. REACH registered; GHS labels available. OEM approvals depend on
final treat rates and viscosity grade.