Is there any disadvantage or advantage to having turn downs?
Sound?
Exhaust fumes that can leek into the cab?

 

I had dumps with both of my true dual set-ups. The Flowmaster Deltaflow 40 series sounded like crap, wasn't deep or loud at all. I think the x-pipe might of had something to do with that though. The dynomax bullets sounded pretty damn good. They were a little too loud in the cab and thats why I've got the 4 x 22 in chrome tips sticking straight out the back. I never had any problems with exhaust fumes leaking in the cab. Just my experiences...

 

I tend to like the sound of a dumped exhaust. It also happens to be cheaper usually than running them all the way out the back.

 

I also have my muffler dumped makes the truck alot cleaner too then havin some tips comming out the back i havent had fumes leak into my truck yet and i love the sound

 

I dumped mind to avoid the cost of good looking tips or having ugly cheap ones sticking out the back.