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Service · Thermal · Driveline · Polyurea Motor Grease

EV Fluid Formulation
R&D From India

Independent formulation R&D for the three classes of fluid the electric powertrain actually needs — e-thermal coolant for battery packs and power-electronics, low-viscosity e-axle fluid for combined motor-and-gearbox units, and polyurea-thickened dielectric grease for hub-motor and high-speed wheel bearings. Built for the Indian EV programme — FAME II, PLI, two-wheelers, three-wheelers, commercial e-LCVs and passenger e-cars.

3
EV Fluid Classes
<25 pS/m
Low Conductivity Target
Full ISO
Test Method Coverage
India + Export
Domestic & Overseas Trials
Why EVs Need Their Own Fluids

An ICE Lubricant
Will Damage an EV

The chemistry that makes a conventional engine oil or ATF work — sulphur-phosphorus EP additives, calcium and magnesium detergents, zinc-based anti-wear (ZDDP) — is exactly the chemistry that attacks an EV. The three fundamental differences are copper-wire corrosion, electrical conductivity, and a thermal-management duty cycle that ICE oils were never designed for.

Copper-wire corrosion. An ICE engine has no live copper in contact with the oil. An EV e-axle and a battery cooling loop run motor windings, bus-bars and connectors directly in or near the fluid path. Sulphur from EP additives and active acid species from ZDDP decomposition attack copper — and the ASTM D130 copper-strip result on a conventional ATF in an EV environment will typically degrade to a 3a or 4a rating within 100 hours of operation.

Electrical conductivity. A fluid in contact with energised windings becomes part of the electrical circuit. If its conductivity is too high it carries leakage current, generates galvanic corrosion of metallic components, accelerates bearing fluting (electrical-discharge pitting of rolling elements) and degrades the fluid itself by oxidation. Target conductivity for direct-cooled traction motors and battery immersion is below 25 pS/m (ASTM D2624). Conventional ATF measures 1,000 to 3,000 pS/m — two orders of magnitude too high.

Thermal-management duty cycle. ICE oil sees the engine block at 100 to 120°C in steady state, with the oil itself peaking around 130°C. An EV thermal fluid in a battery pack must run flat at 20 to 60°C for cell longevity, while a power-electronics inverter cold-plate runs at 70 to 90°C and a traction motor stator can spike to 150°C. The fluid must move heat without phase-changing, without foaming, and without losing dielectric integrity across that whole window.

The 3 Categories of EV Fluid

Three Different Chemistries —
One Vehicle

e-THERMAL
Battery & Power-Electronics Cooling Fluid
A low-viscosity dielectric fluid for direct or indirect cooling of lithium-ion battery packs and inverter cold-plates. Base oil: PAO 4 with a polyol-ester polarity carrier — typical KV40 below 18 cSt. Conductivity targeted below 25 pS/m (ASTM D2624). Dielectric strength above 35 kV (IEC 60156). Thermal conductivity above 0.13 W/m·K. Flash point above 200°C (ASTM D92). Foaming under 50/0 ml (ASTM D892). Designed for both immersion-cooled and cold-plate architectures.
Battery + Inverter
e-TRANSMISSION
e-Axle / e-Drive Combined Fluid
For combined motor-plus-gearbox e-axles where one fluid lubricates the reduction gear set, cools the motor windings, and contacts live copper. KV100 targeted between 3 and 5 cSt — far lower than any conventional ATF. Wear protection (ASTM D4172 four-ball) within EV-compatible chemistry — no sulphur EP, no ZDDP, no calcium detergent. Copper passivation through ash-free chemistry. Conductivity below 500 pS/m. Compatible with insulation films, magnet wire enamel and electrical-grade epoxies.
e-Axle Single-Sump
e-GREASE
Hub-Motor & High-Speed Bearing Grease
A polyurea-thickened grease for wheel-hub motors, high-speed traction-motor bearings and steer-by-wire actuators. Polyurea (di-urea or tetra-urea) thickener at 8 to 14% — ash-free, no soap chemistry. Synthetic base oil (PAO or ester blend). Dropping point above 260°C. Speed factor (n·dm) above 1,000,000 — necessary for the 30,000+ rpm seen in modern hub-motor designs. Dielectric strength preserved. Operating window minus 40 to plus 180°C.
Hub & Traction Motors
Test Methods

The ASTM & IEC Tests
Every EV Fluid Must Pass

PropertyMethodTypical TargetWhy It Matters
Electrical conductivityASTM D2624<25 pS/m (immersion) · <500 pS/m (e-axle)Prevents leakage current, galvanic corrosion and bearing fluting in live-winding environments
Dielectric breakdown strengthIEC 60156>35 kV (e-thermal) · >25 kV (e-grease)Confirms the fluid will not arc-over between energised windings or terminals
Copper-strip corrosionASTM D1301a or 1b at 100°C / 3hVerifies the additive system will not attack motor windings, bus-bars or terminals
Four-ball wear scarASTM D4172<0.45 mm at 40 kgfConfirms wear protection for the reduction gear set without sulphur EP chemistry
Flash point (closed cup)ASTM D92 / D93>200°C (e-thermal) · >220°C (e-axle)Fire safety in the event of fluid leak onto an energised stator or cell wall
Pour pointASTM D97<-40°C (cold-climate) · <-30°C (general)Cold-start behaviour for Ladakh, Kashmir, GCC winter and European export markets
Kinematic viscosityASTM D445e-axle 3-5 cSt @ 100°C · e-thermal <18 cSt @ 40°CLow viscosity is essential — both for fuel-economy-equivalent range and for fast heat removal
Foaming tendencyASTM D892Seq I/II/III <50/0 mlFoam destroys both heat-transfer efficiency and dielectric integrity
Oxidation stabilityASTM D2272 (RPVOT)>300 min (synthetic)Long change interval — EV fluid is expected to run 100,000 to 250,000 km in service
The Independent-Formulator Wedge

Why No Commercial EV-Fluid
Additive Pack Is Good Enough Yet

The major additive houses — Lubrizol, Infineum, Afton, Chevron Oronite — each have an EV product line, and each line is built around the chemistry they already make at scale. That means a 2024-vintage EV pack from one supplier will excel at copper-strip but struggle at conductivity; another supplier's pack will pass conductivity but show foaming issues; a third will offer a balanced pack but at a treat cost that adds ₹40 to ₹60 per litre over a comparable ATF. None of the commercial packs is yet universally good — and none is yet cheap.

That is the wedge for an independent formulator with multi-supplier access. Instead of taking one supplier's full pack, we build a hybrid: a copper-passivator and metal-deactivator from supplier A, a foam control system from supplier B, an ash-free anti-wear from supplier C, the right base-oil-to-ester ratio for the conductivity target, and a finished package treat cost typically 15 to 30% below the equivalent commercial EV pack. That is impossible inside the structure of a contract blender tied to one additive supplier. It is the day-to-day job of an independent additive development consultant.

Indian EV Market Context

FAME II, PLI and the
Indian OEM Landscape

India's EV programme is no longer speculative. FAME II has subsidised over 1.5 million electric two- and three-wheelers. The Production-Linked Incentive (PLI) scheme for Advanced Chemistry Cell (ACC) batteries and Automobile / Auto-Components has committed roughly ₹26,000 crore of incentive across cells, packs and complete vehicles. Every major Indian OEM is now committed to an EV roadmap.

The active OEM landscape Lubechem is engaging with covers: Tata Motors (Nexon EV, Punch EV, Tiago EV, ACE EV light commercial), Mahindra & Mahindra (XUV400, BE 6 and XEV 9e on the INGLO platform), Ola Electric (S1 scooter family + Gen 3 motors), Ather Energy (450 family, Rizta), Hero MotoCorp / Hero Electric / Vida, TVS Motor (iQube), Bajaj Auto (Chetak), Ashok Leyland Switch Mobility, plus the cell ecosystem (Exide ACC plant in Bengaluru, Amara Raja, Reliance New Energy, Ola Cell). Each of these programmes is in active need of validated fluid suppliers — and at the moment, the validated supplier list is overwhelmingly imported product at imported price.

Case Study

Bengaluru EV Startup —
e-Axle Fluid Validated in 12 Weeks

Completed Engagement · e-Axle Fluid R&D
South-India EV Two-Wheeler Maker — Single-Sump e-Axle Fluid for Hub Motor + Reduction Gear
A Bengaluru-based electric two-wheeler startup operating in the performance-scooter segment had finished its mechanical e-axle design and needed a single-sump fluid that could lubricate the reduction gear, cool the motor stator, and run in contact with the bus-bar terminations. The team had tried a commercial Group III ATF in development units and was seeing premature copper discolouration on the busbars after 200 hours of dyno cycling.
We re-formulated on a PAO 4 / polyol-ester 80:20 base (KV100 = 4.2 cSt), removed all sulphur EP chemistry, replaced the calcium detergent with an ashless dispersant, dosed an aryl-amine antioxidant and a benzotriazole copper passivator at carefully tuned treat rates, and added a silicone-free defoamer. First lab samples were delivered at week 3. ASTM D130 returned 1a after 100°C / 3h. ASTM D2624 conductivity measured 380 pS/m. Four-ball wear scar at 40 kgf was 0.41 mm. The startup's 12-week dyno cycle ran clean with no copper transport and a stator-coil temperature 4°C below the baseline ATF case.
Timeline
12 weeks formulation start to dyno validation
Copper-Strip Result
1a (vs 3a baseline ATF)
Stator Temperature
4°C reduction vs baseline
Treat-Cost Position
22% under commercial EV-pack benchmark
Questions & Answers

Frequently Asked About
EV Fluid Formulation

Can existing ATF be used for an EV e-axle?

No. Conventional ATF — Dexron, Mercon, JASO 1A, any LV-spec — was designed for ICE automatic gearboxes where there is no live copper in contact with the oil. The sulphur-phosphorus EP additives and ZDDP-type anti-wear chemistry will attack the motor windings, bus-bars and connector terminations. Electrical conductivity is also typically 1,000 to 3,000 pS/m — two orders of magnitude above an EV-acceptable level.

Some development teams use a conventional ATF for initial mechanical commissioning of an e-axle and switch to an EV-specific fluid for endurance testing. That is acceptable for mechanical de-risking but the durability data from such a phase is not transferable.

What is the conductivity limit for an EV thermal fluid?

The target depends on the cooling architecture. For direct-immersion battery cooling and direct-cooled traction motors (fluid in physical contact with the winding) the conductivity target is below 25 pS/m measured by ASTM D2624. For an indirect cooling loop (cold-plate, jacketed-stator) the limit is more relaxed — typically below 500 pS/m is acceptable.

An EV-grade dielectric base oil starts at 1 to 3 pS/m. Conductivity rises with additive load — every additive in the package contributes, and a poorly-chosen detergent can take the finished fluid above 1,000 pS/m. This is the single biggest reason an EV fluid cannot just be a re-labelled ATF.

Is OEM approval needed before commercialising an EV fluid?

For aftermarket sale through retail and distributor channels, the requirement is a BIS test-data package against the closest applicable Indian standard, a TDS and an SDS — same as any other lubricant launched in India. We prepare all three through our regulatory compliance service.

For OEM factory-fill supply (going into Tata, Mahindra, Ola, Ather, Hero, TVS etc. on the production line) the relevant OEM will run its own bench and vehicle programme. This typically takes 9 to 18 months and is the gating step into the OE supply chain.

Polyurea vs lithium for an EV motor grease?

Polyurea is preferred for EV applications. Lithium and lithium-complex thickeners are metal-soap chemistry — the soap itself is conductive and the thickener decomposition products are mildly acidic. Polyurea is ash-free, dielectric and significantly better at the 30,000+ rpm speeds that EV hub motors and high-pole-count traction motors run at.

Polyurea greases also give a higher dropping point (typically 260 to 280°C vs lithium-complex at 240 to 260°C), longer life in oxidation-stability bench tests, and a broader operating window. The cost-per-kg is higher than lithium, but on a cost-per-service-hour basis polyurea wins comfortably for EV duty.

Which base oil is best for an e-axle fluid?
A PAO-ester blend (typically PAO 4 with 15 to 25% polyol-ester) is the dominant choice for premium e-axle fluids. PAO contributes low pour point, low conductivity, and very high oxidation stability. The polyol-ester contributes polarity (needed for additive solubilisation and for copper passivation) and dielectric integrity. Mineral Group III is acceptable for cost-sensitive aftermarket grades but cannot match either the low-temperature behaviour or the long-life durability of PAO-ester for premium OEM-target programmes.
What is the minimum order quantity for an EV-fluid trial batch?
Lab-scale samples for OEM trials are typically 5 to 50 litres — enough for OEM bench and component-level testing. First commercial pilot batches are usually 200 to 1,000 litres, blended at a contract blender we audit and supervise (or at the client's own plant where one exists). There is no fixed MOQ — we scale to the engagement. For grease, lab samples are 1 to 10 kg, and first commercial batches are 50 to 200 kg.
Related Services

EV Fluid Is Where
Three Practices Meet

Develop Your EV Fluid Range —
Free 30-Minute Scoping Call

Tell us which class of EV fluid you need (thermal, e-axle, motor grease) and where you are in your programme. We respond within one business day with an honest assessment, indicative timeline and indicative treat-cost position.