10W-40 is the most segment-versatile SAE grade in the Indian market — the dominant motorcycle 4T engine oil for premium bikes (Royal Enfield, KTM, Honda CB350, Bajaj Dominar) under JASO MA2 friction specification, and simultaneously a universal multi-fleet car / light-commercial oil under API SN/CF. This guide walks through both variants — Group II base oil selection, OCP viscosity modifier, semi-synthetic DI package, JASO MA2 friction chemistry, and the four-step manufacturing process with BIS IS 13656 pass targets.
The “10W-40” designation comes from SAE J300, the Society of Automotive Engineers viscosity classification for engine oils. It is the most popular motorcycle engine oil grade in India and a credible universal multi-fleet car / light-commercial multigrade.
10W is the winter rating — it commits the oil to a maximum cold-crank simulator viscosity of 7,000 cP at −25 °C (ASTM D5293) and pumpability at −30 °C (ASTM D4684 MRV 60,000 cP max). For Indian motorcycle and light vehicle operation this is more than enough cold-start margin.
40 is the high-temperature rating — KV100 between 12.5 and 16.3 cSt (ASTM D445) and HTHS of 3.5 cP minimum at 150 °C (ASTM D5481). For motorcycle 4T applications the 40-grade viscosity is essential — motorcycle engines run hotter than car engines (gearbox shares the sump, smaller sump volume per kW) and the bearing protection of 40-grade is non-negotiable.
10W-40 occupies the sweet spot for medium-displacement motorcycles (200–500 cc), making it the bestselling motorcycle oil viscosity in India by volume. It can be formulated economically on Group II base oil, keeping it affordable for high-volume 4T motorcycle and rural multi-fleet applications.
| Component | Function | Typical % (m/m) | Notes |
|---|---|---|---|
| Base oil — Group II 4 cSt | Light-cut backbone — cold-crank performance | 25–35% | Chevron 110N / IOCL Yubase G2 4 |
| Base oil — Group II 6 cSt | Heavy-cut backbone — KV100 contribution | 40–50% | Chevron 220R / IOCL Yubase G2 6 |
| Base oil — Group III 4 cSt (semi-synth) | NOACK and oxidation boost for semi-synthetic claim | 10–25% | Optional — semi-synthetic variant only |
| VII — OCP polymer (10–12% active) | Viscosity index improvement | 8–10% | Heavier than 10W-30 due to wider 10W-40 spread |
| JASO MA2 DI package (commercial) | Detergent + dispersant + ZDDP + antioxidant; no friction modifier | 9–11.5% | Lubrizol LZ7708, Infineum F4017, Oronite OLOA 59700 |
| Overbased Ca sulfonate (component blend) | Detergent — piston deposit control, TBN | 2.2–3.5% | TBN target 9–11 mgKOH/g for motorcycle |
| PIBSI dispersant | Sludge control, ring deposit suppression | 3.5–5% | Motorcycle 4T benefits from rich dispersancy |
| Primary alkyl ZDDP | Antiwear — valve train and gearbox wear protection | 1.0–1.3% | Delivers 0.10–0.13% P; no P cap in JASO MA2 |
| Alkylated diphenylamine (ADPA) | Antioxidant — high-temperature stability | 0.3–0.7% | Important for motorcycle high-temperature operation |
| Pour point depressant (PMA) | Lowers pour point of Group II base oil blend | 0.15–0.3% | Standard PMA |
| Silicone defoamer | Suppresses foaming during operation | 5–15 ppm | Dilute before addition |
| NO friction modifier (MoDTC / GMO) | Excluded — would cause wet-clutch slip | 0% | Critical for JASO MA2 friction pass |
The defining chemistry difference for motorcycle 10W-40 JASO MA2 is the absence of friction modifiers (MoDTC, GMO, fatty amides). PCMO friction modifiers cause the wet clutch to slip; JASO MA2 friction tests specifically detect and disqualify such formulations. A car-oriented 10W-40 SN with MoDTC must not be used in a wet-clutch motorcycle.
| Property | JASO MA2 (motorcycle) | API SN (car PCMO) | API SN / CF universal | SL / CF mineral |
|---|---|---|---|---|
| Target engines | Premium 4T motorcycles | BS-IV petrol PCMO | Mixed petrol / light diesel fleet | Older mineral fleet |
| Friction modifier | None (clutch friction) | MoDTC / GMO ok | Limited / mild | None |
| HTHS @ 150 °C | 3.5 cP min | 3.5 cP min | 3.5 cP min | 3.5 cP min |
| Phosphorus (D5185) | 0.10–0.13% | 0.06–0.08% | 0.08–0.10% | 0.10–0.12% |
| Sulphated ash (D874) | 1.1–1.4% | 1.0–1.1% | 1.1–1.4% | 1.2–1.5% |
| NOACK volatility | 15% max (typ) | 15% max | 15% max | No limit (15–22%) |
| Base oil group | Group II + opt Gp III | Group II | Group II | Group I |
| Typical DI pack treat rate | 9.5–11.5% | 9–11% | 9.5–11.5% | 8–10% |
| JASO friction certification | Required | Not applicable | Not done | Not done |
| Indicative cost | Rs 145–180 / L | Rs 130–160 / L | Rs 125–155 / L | Rs 95–125 / L |
JASO MA2 is the right claim for any motorcycle 10W-40. Cars and light commercial vehicles that don’t need wet-clutch friction should use API SN (or SP); using a JASO MA2 oil in a car PCMO application is harmless but the friction modifier absence means the fuel economy benefit is given up.
| Property | ASTM Method | IS 13656 Limit | Recommended Formulation Target |
|---|---|---|---|
| KV @ 100 °C | D445 | 12.5–16.3 cSt | 14.0–14.6 cSt |
| KV @ 40 °C | D445 | Report | 92–105 cSt |
| Viscosity Index | D2270 | 140 min | 150–160 |
| CCS @ −25 °C | D5293 | 7,000 cP max | 5,800–6,500 cP |
| MRV @ −30 °C | D4684 | 60,000 cP max | 30,000–42,000 cP |
| HTHS @ 150 °C | D4683 | 3.5 cP min | 3.7–4.0 cP |
| Pour point | D97 | −24 °C max | −30 to −36 °C |
| Flash point (COC) | D92 | 200 °C min | 220–235 °C |
| TBN | D2896 | 7 mgKOH/g min | 9–11 mgKOH/g |
| Sulphated ash | D874 | 1.5% max | 1.15–1.35% |
| Four-ball wear scar | D4172 | 0.6 mm max | 0.40–0.48 mm |
| Foam Seq I / II / III | D892 | 10/0, 50/0, 10/0 ml max | Nil / nil / nil |
For a motorcycle claim, the additional friction test (JASO T903) is run by a JASO-accredited lab. The static and dynamic friction coefficients must fall within the MA2 window. Most Indian motorcycle formulators contract this test out — few in-house labs have the kit.
Both — 10W-40 is the most versatile multi-segment SAE grade in India. It is the standard motorcycle 4T engine oil for premium bikes (Royal Enfield, KTM, RE Continental GT, Honda CB350) under JASO MA2 friction specification, and simultaneously a universal multi-fleet car / light commercial oil under API SN/CF. The chemistry differs — motorcycle 10W-40 omits friction modifiers and uses JASO MA2 friction-neutral formulation, while car-PCMO 10W-40 can include MoDTC / GMO for fuel economy.
JASO MA2 is the Japanese Automobile Standards Organization friction specification for wet-clutch motorcycles. It defines a friction coefficient range that ensures the wet clutch (which shares engine oil with the crankcase) engages crisply without slipping. JASO MA2 is more stringent than MA. PCMO friction modifiers like MoDTC and GMO cause clutch slip and are explicitly excluded from JASO MA2 formulations. Certification requires the JASO T903 friction test at an accredited lab.
Motorcycle 10W-40 JASO MA2 uses ZDDP at 1.0 to 1.3% delivering 0.10 to 0.13% phosphorus. Motorcycle engines run hotter than car engines (gearbox in oil sump, smaller sump volume per kW) and benefit from richer ZDDP — particularly for cam, valve, and gearbox wear protection. JASO MA2 has no P cap like API SP, allowing the higher treat rate. For API SN car-multi-fleet 10W-40, ZDDP is reduced to 0.7–0.9% for three-way catalyst compatibility.
10W-40 targets HTHS of 3.5 cP min at 150 °C (ASTM D4683) — same as 5W-40 and 15W-40. For motorcycle 10W-40 the design target stretches to 3.7–4.0 cP because of the higher operating temperatures and shared gearbox loads (the engine oil also lubricates the transmission gears in most motorcycles). For universal multi-fleet API SN/CF the target is 3.5–3.7 cP.
Yes for older API SF/SG/SJ/SL claims on Group I base — this is the workhorse for the budget motorcycle and rural multi-fleet segments. For SN/CF and JASO MA2 modern claims, Group II is preferred for NOACK and oxidation compliance. A “semi-synthetic” 10W-40 uses a Group III + Group II blend (typically 15–30% Group III). True full-synthetic 10W-40 is rare in India — most premium positioning has moved to 5W-40 or 5W-30 because those grades inherently require Group III.
Direct material cost for a Group I API SL 10W-40 ranges from Rs 105 to 130 per litre. API SN/CF on Group II runs Rs 125 to 155. Motorcycle JASO MA2 10W-40 semi-synthetic runs Rs 145 to 180. Full-synthetic 10W-40 on Group III runs Rs 175 to 210. Add Rs 6 to 12 per litre for packaging (motorcycle bottles are typically 800 mL–1 L), labour, and overhead. Motorcycle 10W-40 retails at Rs 320–450 per litre in the Indian aftermarket — gross margins are attractive.
Strongly discouraged. Car PCMO 10W-40 typically contains friction modifiers (MoDTC, GMO) for fuel economy. These cause wet-clutch slip in motorcycles — the clutch will not engage crisply, you will feel slip on hard acceleration, and over months the clutch plates glaze and need replacement. Always use a JASO MA2-certified motorcycle 10W-40. The certification label on the bottle (JASO T903:2016 MA2) is the indicator.
Share your target market (motorcycle JASO MA2 / car multi-fleet SN / universal CF mineral), production scale, and price band. We’ll respond within one business day with an indicative formulation plan, BOM, and BIS certification roadmap.