This document provides the technical guidance required for the use of Sinopec T700 15W40 and Sinopec T700 10W30 in heavy-duty diesel engines and associated commercial drivetrain systems.
Equipment covered
- Commercial trucks and transport fleets
- Construction and off-road diesel equipment
- Municipal and mixed fleets
Key risks addressed
- Aftertreatment compatibility
- Wear protection under high load
- Oil consumption and viscosity stability
- Axle and drivetrain wear under sustained load conditions
- Thermal stress in differential and transmission systems
Engine oil technical basis
Sinopec T700 oils are positioned to ACEA E9 and API CK-4, which are specified for modern diesel engines fitted with EGR, SCR and DPF systems.
Heavy-duty diesel engine oils used in commercial fleet applications must provide soot handling capability, oxidation resistance, viscosity stability, wear protection, and compatibility with emissions control systems operating under extended load and drain interval conditions.
Engine oil grade selection
| Operating condition | Grade | Rationale |
|---|---|---|
| General fleet operation | T700 15W40 | Proven viscosity stability across wide temperature ranges |
| Fuel efficiency or cold start focus | T700 10W30 | Lower viscosity supports reduced internal drag |
Automotive gear oil technical basis
Heavy-duty commercial vehicles operate with heavily loaded drive axles, differentials, and manual transmissions that require extreme-pressure gear lubricants designed to protect against wear, micropitting, and thermal degradation under sustained mechanical stress.
Automotive gear oils used in fleet drivetrain systems are commonly aligned with API GL-5 performance requirements, with viscosity grades selected according to axle loading, operating temperature, duty cycle, and OEM approval requirements.
Automotive gear oil viscosity selection
| Operating condition | Typical viscosity grade | Selection rationale |
|---|---|---|
| General fleet axle operation | SAE 80W-90 GL-5 | Provides balanced wear protection and durability across mixed operating conditions |
| Long-haul or extended drain operation | SAE 75W-90 GL-5 | Improves low-temperature flow characteristics and thermal stability during sustained operation |
| High load or elevated operating temperature service | SAE 75W-140 GL-5 | Provides enhanced film strength and protection under severe thermal and mechanical stress |
Equivalency statement
Sinopec T700 15W40 and 10W30 are suitable for use where ACEA E9 or API CK-4 engine oils are specified, subject to OEM viscosity requirements.
Associated drivetrain lubricants should also be selected in accordance with axle and transmission manufacturer requirements, including the correct API gear oil performance category and viscosity grade for the intended operating conditions.
Changeover guidance
- Changeover at scheduled oil change
- No flushing required when replacing oils of the same category
- Verification of axle and transmission lubricant specifications should form part of any fleet lubricant transition review
- Drain intervals and approval requirements should remain aligned with OEM maintenance documentation