Crucially: Check your owner's manual for the manufacturer's specific recommendation. While 15W-40 is a common and often-recommended choice for older diesels, the manual is the ultimate authority.
Important Considerations:
* API Certification: Look for an oil that meets the API (American Petroleum Institute) standards for diesel engines. Older standards like CD or CC might be suitable, but a modern equivalent like CI-4 or even CJ-4 (though possibly overkill) is fine as well.
* Additives: Consider using an oil with additives designed for older diesel engines to help with wear and tear. Some older diesel engines benefit from zinc-rich oils, but check compatibility first.
* Oil Filter: Always use a good quality oil filter specifically designed for your engine.
* Climate: If you live in a very cold climate, a 15W-40 may be better suited than a straight 30-weight for easier cold starts.
Don't hesitate to consult a local mechanic specializing in older vehicles or your Ford dealership parts department for advice. They can confirm the proper oil viscosity and API rating.
