Which is better? I would think coil over plug would be the best because there are no high voltage plug wires and the fact that the electrical generation is directly to the plug.

My F150 is EDIS and my Dakota is COP... and I can't really tell which is better.

 

Glowplugs.

 

COP - but the way Ford does it on the 4.6/5.4 is a pain in the ***.

 

COP is lighter and there's less clutter in the engine compartment, but the parts of an EDIS/HDR ignition (mainly, the coil pack) are far less failure prone than individual coils.

COP ignitions tend to dump a lot of RF interference when the coils themselves start flaking out - this can affect all the systems throughout the vehicle, causing weird things like false overheat DTCs, erratic gauge operation, harsh/erratic trans shifts, and a bunch of other things. This isn't as big a problem on EDIS/HDR ignitions with shielded plug wires.

 

Thanks for the info. I would have thought the EDIS would have dumped more RF because the plug wires acting like small antennas.

Interesting though... thanks!

 

Most plug wires today are shielded pretty well, even the cheapest ones. COPs however practically have no shielding built in.

 

I think you mean Coil on Plug. A coil over is the suspension.