Automatic Transmission Fluid is the most technically demanding lubricant after marine cylinder oil — it must simultaneously transmit hydraulic pressure, lubricate gears, control friction at the clutch plates, and cool the transmission. The friction static/dynamic ratio specification is the technical hurdle that filters out most aftermarket formulations. This guide gives the recommended Dexron VI BOM, the friction modifier chemistry, BIS / OEM positioning and Indian brand benchmarks for Castrol Transmax, Shell Spirax, Mobil ATF 3309. ATF sits within our wider automotive lubricant formulation practice covering engine oils, gear oils and driveline fluids.
| Component group | Typical role | Typical share |
|---|---|---|
| Base oil(s) | Carrier fluid (Group I–IV as required) | ~75–85% |
| Detergent–inhibitor (DI) additive package | Detergency, dispersancy, anti-wear, antioxidant, TBN | ~8–14% |
| Viscosity-index improver | Viscosity–temperature control (multigrades) | ~4–10% |
| Pour-point depressant & anti-foam | Cold flow & foam control | <1% |
Indicative high-level composition only. The exact components, treat rates, performance additives and approved suppliers are shared under NDA as part of a Lubechem formulation engagement.
Process: blend Group III + PAO at 70 °C with low-shear; charge DI package and seal-swell ester; dose PMA VII slowly at 65 °C; add FM, AO, CI; foam inhibitor blend last with 5-min mix only; final red dye. QC: KV100 6.0-6.4 cSt, VI ≥150, pour <-50 °C, foam D892 Seq I <25/0/0, friction static/dynamic 0.92-1.05 (SAE No.2 friction machine). Ex-works cost ₹150-220 / L at 5 MT batch. Pack in 1 L can, 4 L jug, 200 L drum.
| ATF Family | OEM | KV100 (cSt) | Critical Spec |
|---|---|---|---|
| Dexron VI | General Motors | 6.0 | Static/dynamic friction, shear stability |
| Mercon V / LV | Ford | 5.7 / 5.5 | Low-viscosity, fuel economy |
| ATF+4 | Chrysler / Stellantis | 7.5 | Anti-shudder, lifetime fill |
| CVT — Honda HCF-2 | Honda | 7.0 | HIGH friction (opposite of ATF) |
| CVT — Nissan NS-3 | Nissan / Maruti | 7.2 | HIGH friction, steel-belt grip |
| DCT — VW G 052 182 | VW / Audi / Skoda | 5.5 | Dual-clutch friction, oxidation |
Automatic Transmission Fluid (ATF) is the specialised hydraulic + lubricant + friction-modified fluid used inside automatic, CVT and DCT transmissions. It must do four jobs simultaneously: transmit hydraulic pressure, lubricate gears and bearings, provide controlled friction at the clutch plates, and cool the transmission.
Major families: GM Dexron III / VI, Ford Mercon V / LV, Chrysler ATF+4, JASO 1A (Japan), CVT-specific (Honda HCF-2, Nissan NS-3), DCT-specific (VW G 052 182). Base oil Group III / PAO synthetic, KV100 5.5-7.5 cSt, friction modifier critical.
Dexron VI ATF BOM (%): Group III 4 cSt 78%, PAO 4 cSt 5%, ATF DI package 5.5%, FM (oleamide + MoDTC blend) 0.6%, PMA VII + PPD 5%, phenolic AO 0.6%, aminic AO 0.4%, ASA + thiadiazole CI 0.4%, foam inhibitor 200 ppm, seal swell ester (TMP-trioleate) 4%, red dye 200 ppm, balance Group III diluent.
KV100 6.0-6.4 cSt, VI 150+, pour <-50 °C, friction static/dynamic ratio 0.92-1.05 per GM Dexron VI spec.
Dexron III (legacy 1993-2005) used Group I/II mineral base with conventional FM. Acceptable for older GM, Ford, Chrysler automatic transmissions through 2006 model year. KV100 ~7.5 cSt, VI ~150. Dexron VI (2006-current) requires synthetic base, tighter friction modifier balance, longer drain, better shear stability.
Dexron VI is backwards-compatible (works in older Dexron III transmissions) but Dexron III is NOT forward-compatible. Modern blender produces only Dexron VI for new market.
ATF clutches engage via wet-friction discs — paper-fibre disc against steel reactor plate, lubricated by ATF. Friction profile matters: too high static friction → harsh engagement; too low → clutch slips. FM tunes static/dynamic/slip friction balance.
GM Dexron VI specifies static:dynamic friction ratio 0.92-1.05 — outside this range the transmission shifts harshly or slips. FM represents the highest-stakes additive in ATF formulation. Getting FM right is the technical hurdle for new ATF formulations.
CVT (continuously variable transmission) uses metal-belt-on-pulley friction transfer — opposite friction requirement: HIGH friction needed for belt-on-pulley grip. CVT fluid (Honda HCF-2, Nissan NS-3, Toyota TC) uses high-friction-stable additive package. Wrong fluid in CVT causes belt slippage and immediate damage.
DCT uses two parallel clutches that pre-engage — needs ATF-like friction profile plus better cooling and oxidation life. Mercedes 7G-DCT, Audi/VW DSG use DCT-specific fluids (G 052 182, MB 236.21). Each fluid family is incompatible; blender must produce SKU per family.
India ATF market: 4W aftermarket dominated by Maruti Suzuki (NS-3 CVT for Baleno/Brezza, ATF SP-IV for older Vitara), Hyundai (ATF+4, DCT for Verna/Creta), Tata Motors (Castrol Transmax for AMT), Mahindra (Dexron III for older XUV).
Brands: Castrol Transmax Dexron VI / CVT / DCT, Shell Spirax S6 ATF, Mobil ATF 3309, Total Quartz ATF, IOCL Servo ATF, BPCL Mak ATF, HPCL ATF. ₹240-580 / L retail. Lubechem custom (LC-ATF-DEX-VI) ex-works ₹150-220/L at 5+ MT batch.
BIS IS 17073:2019 covers ATF (Dexron II/III equivalent class). Newer Dexron VI / CVT / DCT specs are OEM-licensed (GM, Toyota) and not directly covered by BIS — Indian blenders must qualify against the OEM specification at the OEM's authorised lab (cost $50,000-200,000 USD per fluid family).
For most Indian aftermarket, OEM-equivalent positioning ('suitable for Dexron VI applications') is sold under blender's own brand without formal GM license — legally acceptable but excludes blender from factory-fill OEM contracts. Full GM Dexron VI license unlocks OEM dealership channel.
Share your target spec (Dexron VI / CVT / DCT / ATF+4), volume and brand positioning. We respond within one business day with the BOM, FM tuning plan and ex-works cost.