Buying an 09 and I'm wondering how many people actually like the MDS. I've seen several post that are negative but, was wondering if thay are a big headache and do they improve gas mileage at all.

 

It's costly when it gets old and there is a malfunction. Personally I would rather not have it.

 

My opinion: Giant headache!

In 4 cylinder mode the motor bogs down before switching back to a V8.

I don't normally drive conservative and do not care about fuel consumption. Clarification, this is a heavy 390 hp truck. It has fuel injection. That's good enough for me. I don't need some annoying gimmick.

I have the 5 speed with 3:55 rear. Maybe other year/combinations aren't as noticeable.

It's the only thing that I don't like about my truck.

 

I like it fine in my 2009 CC. I don't really notice it at all unless I look down at the indicator. My truck is OEM stock and at almost 102k miles has never had an issue with the engine (except broken manifold studs). It does improve the MPGs some.

 

Same here, I like it in my 2009 and it runs seamlessly for me with no troubles. Just make sure you use the proper weight oil for the engine and service it regularly.

It only takes a few milliseconds for the system to switch from 8 to 4 and then back from 4 to 8, not enough time to bog an engine down