Ford 2011 Flex Owner's Manual page 344

Maintenance and Specifications
Engine oil and filter recommendations
3.5L V6 engine
Look for this certification
trademark.
Use SAE 5W-20 engine oil
Only use oils certified for gasoline engines by the American Petroleum
Institute (API). An oil with this trademark symbol conforms to the
current engine and emission system protection standards and fuel
economy requirements of the International Lubricant Standardization and
Approval Committee (ILSAC), comprised of U.S. and Japanese
automobile manufacturers.
To protect your engine and engine's warranty, use Motorcraft SAE
5W-20 or an equivalent SAE 5W-20 oil meeting Ford specification
WSS-M2C930-A. SAE 5W-20 oil provides optimum fuel economy and
durability performance meeting all requirements for your
vehicle's engine. Refer to Maintenance product specifications and
capacities later in this section for more information.
Do not use supplemental engine oil additives, cleaners or other engine
treatments. They are unnecessary and could lead to engine damage that
is not covered by Ford warranty.
Change your engine oil according to the appropriate schedule listed in
the scheduled maintenance information.
Ford production and Motorcraft replacement oil filters are designed for
added engine protection and long life. If a replacement oil filter is used
that does not meet Ford material and design specifications, start-up
engine noises or knock may be experienced.
It is recommended you use the appropriate Motorcraft oil filter or
another with equivalent performance for your engine application.
344
2011 Flex (471)
Owners Guide, 1st Printing
USA (fus)