Lubricant FAQ

Start with the vehicle or equipment manual. It gives the required viscosity grade, API or ACEA category and, where relevant, an OEM approval. Match all of those requirements, not just the brand or price. Climate, duty cycle, engine condition and fuel quality can affect the choice. Confirm the final product against its current TDS.

• Engine oil selection guide
• Engine oil range
• Lubricant glossary

They are SAE J300 viscosity grades. The number before W describes cold-start performance; the number after W describes viscosity at high temperature. A lower W number helps cold starting, while a higher second number means a thicker oil at operating temperature. The grade is not a quality rating: API, ACEA and OEM requirements are separate.

• 15W-40 vs 20W-50
• Viscosity terms

Avoid routine mixing of different products or viscosity grades. In an emergency, a top-up with a product that meets the same specification may be acceptable, but the mixed oil may not meet the original performance level. Never mix ATF with CVT fluid or different transmission fluids. Return to the correct oil as soon as practical and record the top-up.

• ATF and CVT definitions

Follow the OEM interval and the severe-service schedule. Fuel quality, dust, idling, short trips, load and after-treatment affect oil life. For fleets, oil analysis can support condition-based intervals, but do not extend beyond the OEM recommendation without data. Use the specified filter and check the oil level regularly.

• Oil selection guide

These are API service categories for gasoline engines. Later categories generally address newer engines, fuels and emission systems, but a later category is not automatically the right choice for every older engine. Use the category required by the manufacturer and check the product TDS for the exact approval.

• API and ACEA terms
• Engine oil range

ACEA is a European set of performance sequences used alongside API. A/B categories cover passenger-car gasoline and diesel engines, C categories cover catalysts and gasoline particulate filters, and E categories cover heavy-duty diesel. If the manual specifies an ACEA category, match it exactly and confirm the OEM approval; viscosity alone is not enough.

• Engine oil selection guide
• ACEA definition

A later API category is not automatically better for a given engine. Newer categories may be designed for lower-sulfur fuel, different after-treatment or tighter emission limits. An older engine may not need them, and some equipment requires a specific OEM approval. Match the requirement in the manual and confirm the product's TDS.

• Diesel category comparison
• Specification guide

These are API heavy-duty diesel categories from different emission periods. CH-4 and CI-4 were developed for older diesel engines and higher-sulfur fuels; CI-4 added better soot and viscosity control for cooled EGR. CJ-4 was introduced for low-sulfur fuel and advanced after-treatment, with limits on ash, phosphorus and sulfur. Use the category required by the engine maker; do not assume the newest letter is suitable for every engine.

• CI-4 vs CH-4 vs CJ-4
• Diesel oil range
• API service categories

ATF and CVT fluid are not interchangeable. A CVT uses a belt or chain and needs a fluid with a specific friction profile; ATF is formulated for clutch, gear and hydraulic behaviour in a conventional automatic. Using the wrong fluid can cause shudder, slip or transmission damage. Match the transmission model and the OEM specification.

• ATF vs CVT comparison
• Transmission fluids

ISO VG 46 and 68 describe viscosity at 40°C; 68 is thicker than 46. The choice depends on the pump manufacturer, operating temperature, start-up temperature, pressure and duty cycle. A hotter system may need a higher grade; a cold climate may need a lower one. Check the equipment manual and the oil's TDS; thicker is not automatically better.

• Hydraulic 46 vs 68
• Hydraulic oil range

Ask for the technical data sheet (TDS) for the exact product, the safety data sheet (SDS), a certificate of analysis (COA) for the batch where available, and evidence of any OEM approval or licence. Confirm pack sizes, batch number, shelf life and storage conditions. A general brand statement is not a substitute for product-specific documents.

• Wholesale enquiry checklist
• TDS, SDS and COA

Include the destination country, your business type, the products and specifications, pack sizes, initial quantity, expected repeat demand and required documents. Add delivery terms and timing, and separate different requirements into lines. Label forecasts as estimates. This makes it easier to confirm MOQ, lead time and a comparable proposal.

• Send an enquiry
• Wholesale checklist