Phillips 66 X/C Aviation Oil 20w-50 Engine Oil

Phillips 66 X/C 20W-50 Aviation Oil

Ashless Dispersant Multigrade Engine Oil for Aircraft Piston Engines

Phillips 66 X/C 20W-50 Aviation Oil is a mineral oil-based, ashless dispersant, multigrade engine oil formulated for year-round use in aircraft piston engines. It is recommended for opposed piston engines and can be used during engine break-in, then continued as the operational oil until TBO when permitted by the engine manufacturer.

Compared with single-grade aviation oils, X/C 20W-50 provides easier cold-weather starting, faster oil circulation at low temperatures, reduced warm-up time, and lower oil consumption in most engines. Its ashless dispersant formulation helps minimize sludge, varnish, piston deposits, and combustion-chamber deposits while maintaining film strength under high loads and elevated operating temperatures.

Key Benefits

• Ashless dispersant SAE 20W-50 aviation engine oil
• Multigrade formulation for year-round use
• Recommended for opposed piston aircraft engines
• Recommended for break-in and continued operation until TBO
• Easier starting and faster oil circulation at low temperatures compared with single-grade oils
• Reduced warm-up time compared with single-grade oils
• Helps minimize sludge, varnish, piston deposits, and combustion-chamber deposits
• High film strength helps protect against wear and piston scuffing
• Protects against rust and corrosion
• Reduces oil consumption in most engines
• Suitable as a replacement for Commercial Grade 65, 80, or 100 single-grade oils where permitted

Applications

X/C 20W-50 is recommended for opposed piston aircraft engines and can replace the following single-grade aviation oils where SAE 20W-50 is permitted:

• Commercial Grade 65
• Commercial Grade 80
• Commercial Grade 100

X/C 20W-50 is used across a wide range of general aviation operations, including flight-school aircraft, charter and cargo operations, aerobatic aircraft, agricultural aircraft, race aircraft, and other compatible opposed-piston engine applications.

Always confirm the required viscosity grade, oil specification, and service recommendations in the aircraft engine manufacturer's current documentation.

Break-In and Normal Operation

X/C 20W-50 is recommended for use during engine break-in and can remain in service as the operational oil until TBO.

X/C 20W-50 is designed to provide cleaner and quicker break-in than traditional all-mineral, non-additized single-grade oils while continuing to provide deposit control and wear protection during normal operation.

Always follow the engine manufacturer's current break-in procedure, particularly after engine overhaul or cylinder replacement.

Ashless Dispersant Performance

The ashless dispersant formulation in X/C 20W-50 helps minimize the formation of:

• Engine sludge
• Varnish
• Piston deposits
• Combustion-chamber deposits

This helps maintain a cleaner engine compared with straight, non-dispersant mineral aviation oils.

Cold-Weather and High-Temperature Performance

X/C 20W-50's multigrade formulation provides easier starting and faster oil circulation at low temperatures compared with single-grade aviation oils. It also reduces warm-up time and supports year-round operation across changing seasonal conditions.

Under high loads and elevated operating temperatures, including takeoff, X/C 20W-50 maintains film strength to help protect against wear and piston scuffing.

The typical pour point is -33°C (-27°F), while the typical flash point is 235°C (455°F).

Meets the Requirements Of

• Avco Lycoming: Material Specification No. 301G
• Pratt & Whitney: Service Bulletin No. 1183 Rev. U
• SAE: J1899
• Teledyne Continental: Material Specification MHS-24B
• U.S. Military: MIL-L-22851D (obsolete) for additive treatment

QPL Approval Number: D07L1-20W-50

Typical Properties

Typical properties are average values and should not be treated as product specifications.

Frequently Asked Questions

What is Phillips 66 X/C 20W-50 Aviation Oil?
Phillips 66 X/C 20W-50 is a mineral oil-based, ashless dispersant, multigrade aviation engine oil designed for opposed piston aircraft engines and year-round operation.

Can Phillips 66 X/C 20W-50 be used for engine break-in?
Yes. X/C 20W-50 is recommended for use during break-in and can remain in service as the operational oil until TBO. Always follow the engine manufacturer's current break-in instructions.

Is Phillips 66 X/C 20W-50 a mineral oil?
Yes. X/C 20W-50 is a mineral oil-based, ashless dispersant multigrade aviation engine oil.

Is Phillips 66 X/C 20W-50 synthetic?
No. X/C 20W-50 is not a synthetic aviation oil. It is a mineral oil-based multigrade formulation.

Is Phillips 66 X/C 20W-50 an ashless dispersant oil?
Yes. X/C 20W-50 uses an ashless dispersant formulation designed to help minimize sludge, varnish, piston deposits, and combustion-chamber deposits.

What aircraft engines use Phillips 66 X/C 20W-50?
X/C 20W-50 is recommended for opposed piston aircraft engines. Always confirm the required viscosity grade and specification in the engine manufacturer's documentation.

Can X/C 20W-50 replace straight-weight aviation oil?
Yes, when permitted by the engine manufacturer. X/C 20W-50 can replace Commercial Grade 65, 80, or 100 single-grade aviation oils without sacrificing performance.

Is Phillips 66 X/C 20W-50 suitable for year-round use?
Yes. X/C 20W-50 is formulated for year-round operation in compatible aircraft piston engines.

What is the pour point of Phillips 66 X/C 20W-50?
The typical pour point is -33°C (-27°F).

Does Phillips 66 X/C 20W-50 meet SAE J1899?
Yes. SAE J1899 is included among the requirements met by X/C Aviation Oil.