Natural Gas Engine Oil
Phillips 66®Guardol NG is a high-quality, dispersant-detergent gas engine oil specially designed for use in vehicular natural gas engines that have slider-follower valve trains. It is formulated with a higher level of antiwear additives than conventional low-ash gas engine oils to meet the enhanced wear protection requirements of diesel engines converted to natural gas service. It is particularly recommended for use ihhn transit buses, school buses, delivery trucks and other vehicles equipped with Cummins, Detroit Diesel or John Deere CNG or LNG engines.

Features & Benefits

• Excellent wear protection for diesel engines converted to natural gas service

• High dispersancy protects against sludge and varnish formation

• Outstanding resistance to oxidation and nitration

• Protects against scuffing and wear

• Protects against valve stem deposits and valve seat recession

• Protects against rust and corrosion

• Good foam resistance


• Transit buses, school buses, delivery trucks and other vehicles equipped with slider-follower CNG or LNG engines

Technical Details

Licenses & Approvals

Guardol NG is OEM-certified for:

• Cummins CES 20085

• Detroit Diesel DFS 93K216 (Series 50G and Series 60G engines)

Guardol NG meets the performance requirements of:

• John Deere 6.8L and 8.1L CNG engines

Additional Details
SAE Grade15W-40
Specific Gravity @ 60°F0.875
Density, lbs/gal @ 60°F7.29
Color, ASTM D15007.5
Flash Point (COC), °C (°F)227 (441)
Pour Point, °C (°F)-36 (-33)
Viscosity, Kinematic
cSt @ 40°C114
cSt @ 100°C15.2
Viscosity Index139
Cold Cranking Viscosity (CCS), cP @ -20°C6300
Sulfated Ash, ASTM D874, wt %0.76
Total Base Number (TBN), ASTM D28966
Phosphorus, wt %0.08
Zinc, wt %0.088