Jeep Commander Forum banner

1 - 8 of 8 Posts

·
Registered
Joined
·
30 Posts
Discussion Starter #1
For those contemplating a non OEM muffler here is a fact you should consider.

The muffler on 2007 Hemi went at 90k miles. New OEM muffler was 1000.00 here in Canada. A full stainless cat-back system MagnaFlow was less than that. Wanting a bit more sound, I went with the cat-back. The sound is awesome except when it runs on 4 cylinders. it produces a loud grumbling sound in the car. Shifting manually into 5 quiets the sound immediately. Running on 8 cyl is actually quieter than running on 4cyl. I know I can prevent this by selecting 5 with the gear lever, but gas mileage will suffer.

When I had the OEM muffler on i could barely detect 4 cyl below 1500 rpm. Now I can hear it at 70mph cutting in and out on hills while in cruise. It runs mostly on 4 if there is no headwind.

This was a surprise to me and hopefully won't be for any of you.
 

·
Registered
Joined
·
139 Posts
Do all Hemi's have MDS? Because i don't think mine does that...
 

·
Administrator
Joined
·
15,249 Posts

·
Premium Member
Joined
·
677 Posts
Does your new exhaust have resonators? The resonators are what quiets it down when in 4 cylinder mode.
All Commander Hemi's have MDS, Hemi's like Top Fuel dragsters and older Hemi's do not.
 

·
Premium Member
Joined
·
677 Posts
Maybe someone with the performance exhausts can comment. One thing you can do is press the tow/haul button. It will keep the trans in one lower gear but it also stops MDS from kicking in.
 
1 - 8 of 8 Posts
Top