That's Fords twin plug ignition system to help reduce emissions
There are ( 6 ) spark plugs
In a 2011 Ford Ranger : The 4.0 litre Single Over Head Cam , V6 engine has : ( 6 spark plugs )
On a 2005 Ford Ranger : The 2.3 liter Dual Over Head Cam , four cylinder engine has : ( 4 spark plugs )
There are ( 6 spark plugs ) on the Ford 4.0 liter V6 engine
The Ford 4.0 liter V6 engine has ( 6 spark plugs )
( 8 spark plugs ) for your 2001 Ford Ranger 2.5 liter 4 cylinder ( with Fords twin plug ignition system )
Motorcraft is best for Ford
On a 2002 Ford Ranger : Check the Vehicle Emissions Control Information ( VECI ) decal in the front of your engine compartment . It will show the type of spark plugs used and the spark plug gap
( 4 ) for the 2002 Ford Ranger 2.3 L - DOHC engine
spark plugs wiring diagram
If you have computer access you can surf to AutoZone.com and type in your vehicle specific information. Their system will have most of the part numbers and products listed that are for your specific vehicle (including the plugs). You don't have to download anything and it is free.
On a 2002 Ford Ranger : The 2.3 liter Dual Over Head Cam four cylinder engine has ( 4 spark plugs )