Not sure where to post this. Does the MDS stop the same 4 cyclinders each time it comes on? if so wouldnt that wear the firing cyclinders more than those? thanks for the info.

 

http://en.wikipedia.org/wiki/Multi-Displacement_System

 

Since the pistons are still moving in the cylinder bore, the wear would be the same. MDS just shuts off 4 injectors and plugs.

BTW my cousin just got an 08QC with the 5.7, he spent around a grand to get the exhaust done but it drives and sounds amazing. The rumble with the new exhaust is killer.

 

Is that headers and all? That's kinda pricey for just pipes and mufflers.
I'd love to do long tubes, but I can't spend that kind of cash and don't want any warranty hassles while under the 3 yr 36K bumper to bumper. I do have the Magnaflow cat-back, they are good with that. Pulled my MIT pipe when I took it in for an oil change Thursday. I think I have an alternator bearing making noise. Sounds like a vacuum leak, but it varies with rpm, not throttle. I'm going to pull the belt tomorrow and see if I can feel the culprit, then take it in Monday afternoon so they can verify and order the part. The mechanic checked Thursday and the parts dept did not have and alt. or idler pulley. Must not go bad often
Anyway, back to the original post, Yes, as mentioned, MDS always shuts off 1,4,6,&7 cylinders. It holds the valved closed as well so that there is no air being pumped thru the cylinders which reduces friction. The best think for MDS is to get a Diablosport Predator and turn it off Especially with louder exhaust!!