I have a new Shine spec. A diffuser installed on my new bumper cover and I just was wondering what some of you guys have to say about the pros and cons between a good quality, well designed functional diffuser as opposed to the same quality of a lip?

My new diffuser took some detailed body work and custom work and looks great, it extends under engine and takes the place of the under shroud/tray (I had an aluminum Zspeed one) and fills in that whole under engine area; a nice lip would have been much easier to install and I could have just kept the aluminum piece.

I hope you get what I'm trying to ask; I'm sure there are diffusers/lips that are junk and are a waste of time, but the good ones definitely work aerodynamically with added down force at speed and directed air flow through cooling system and under car. *I'm just curious because I had looked into some nice JDM lips, but now have an Amuse replica diffuser; not a bad thing at all!

 

As long as it covers the same contiguous area then same difference either way. Obviously would have to see each specific design to be able to compare.