Originally Posted by GriffFX4
What is the size/type bulb there? My OM says it should be 3156, that link shows 921.
Philips uses their own numbering system. The Philips manual at the store lists Philips bulbs size 921 (T16). SuperBrightLED.com also lists 921 and 912 as acceptable sizes for 2009-2013 F-150's. I currently have them installed on my 2013 XLT SCREW and they're awesome. I'll attach a few reference charts.