1. Engine Condition:
* New or Rebuilt Engine: A high-quality synthetic blend or full synthetic oil is recommended for optimal protection and performance.
* Older Engine: If your engine has higher mileage, a conventional oil with a higher viscosity (like 10W-40) may be more appropriate to compensate for wear.
2. Climate and Driving Conditions:
* Cold Weather: Consider a lower viscosity oil (like 5W-30) for easier starting and lubrication in cold temperatures.
* Hot Weather: A higher viscosity oil (like 10W-40 or 20W-50) is preferred in hot weather to prevent excessive thinning and wear.
3. Recommended Oil by Ford:
* Check Your Owner's Manual: The best starting point is to look up your specific 1966 Ford Mustang's engine specifications and recommended oil type in the owner's manual.
4. Oil Viscosity:
* Common Options: Common viscosity grades for inline 6s are 10W-30, 10W-40, and 20W-50. Consult your manual or a mechanic for the best choice based on your engine and climate.
5. Oil Type:
* Conventional: A more affordable option, but may not offer the same level of protection as synthetic blends or full synthetics.
* Synthetic Blend: A good compromise between price and performance, offering better protection and performance than conventional oils.
* Full Synthetic: The most premium option, providing excellent protection and performance, especially in extreme conditions.
6. Oil Additives:
* ZDDP (Zinc Dialkyldithiophosphate): Older engines (pre-1990s) can benefit from a higher ZDDP concentration to protect camshafts and other moving parts.
* Friction Modifiers: These can improve fuel economy and reduce wear.
In Conclusion:
* Consult your 1966 Ford Mustang's owner's manual. This is the most reliable source for recommended oil type and viscosity.
* Consider your engine's condition and your local climate.
* Choose a quality oil from a reputable brand.
If you're unsure about what oil to use, it's always best to consult with a qualified mechanic who can advise you based on your specific vehicle and driving conditions.
