Castrol 15B5C9 Assuron SAE 30 Monograde Heavy-Duty Diesel Engine Oil 5-Gallon Pail

The Castrol Assuron SAE 30 is a high-performance, heavy-duty monograde engine oil formulated for on- and off-highway diesel engines that require API CF-2 or CF specification lubricants. Packaged in a convenient 5-gallon pail, it is well-suited for fleet maintenance, industrial equipment, and older diesel-powered machinery operating in demanding conditions.

Castrol Assuron 30 pairs carefully selected base stocks with a balanced additive package to deliver outstanding protection and cleanliness. Its formula is highly resistant to high-temperature deposit formation, while an elevated dispersant package helps prevent sludge buildup in cooler engine areas.

Key Features:

• SAE 30 Monograde Viscosity — targeted protection for engines specifying a single-grade oil
• API CF-2 / CF Certified — meets or exceeds both API CF-2 and CF service categories
• High-Temperature Deposit Resistance — keeps pistons and combustion areas clean under severe operating conditions
• Advanced Dispersant Package — controls sludge and harmful deposits in cooler engine zones
• Proven On- and Off-Highway Performance — validated in heavy-duty diesel engine applications including generators and industrial equipment
• 5-Gallon Pail — bulk packaging for efficient fleet and shop use

Typical Specifications (SAE 30):

• Kinematic Viscosity @ 40°C: 92.2 cSt (ASTM D-445)
• Kinematic Viscosity @ 100°C: 11.0 cSt (ASTM D-445)
• Viscosity Index: 104 (ASTM D-2270)
• Sulfated Ash: 0.95% wt. (ASTM D-874)
• Total Base Number: 7.4 mg KOH/g (ASTM D-2896)
• Pour Point: -30°C (ASTM D-97)

Castrol Assuron 30 is recommended for older diesel engines — including generators, stationary equipment, and legacy on-highway trucks — that specifically require a monograde oil meeting API CF or CF-2 standards. It is not intended for modern turbocharged diesel engines requiring multigrade or higher API service categories.