Hello. I just bought an '05 R/T and was wondering if there is any indication when the car is operating in "fuel saver mode"...

 

Nope.

 

Look around different forums you will find info on installing a DIY indicator that is not difficult to do.

 

YES!! There is a slight change in the tone of the exhaust, more easily heard with custom exhaust.

 

I was just guessing he was talking about a factory idiot light or something that would tell you when it happens....and there`s not. I`ve never heard a difference with my exhaust , but it`s stock.

 

Even with 2 MagnaFlow mufflers and 4 glasspacks I can hear the change from the smooth V8 sound to the slightly coarse I4 sound. It sounds like money being saved!! I know of NO negatives with the MDS system. I get over 25mpg at 65 on the Interstate. (My '67 Ram-Air GTO that weighed less, and had similar performance, never saw the good side of 10mpg!) I would have bought an SRT8 long ago if it had the MDS system!!

 

easiest way is to just check out the rpm, it will drop when u switch to mds, which would then be audible if u dont have the stereo kickin.

 

"easiest way is to just check out the rpm, it will drop when u switch to mds"


Sorry, but that does not make sense!! The MDS shuts down four cylinders, but that does not change the rpm. If you are cruising in 5th gear with the torque convertor locked up and the rpm dropped, the car would slow down!

With MDS, the valves are held closed and the fuel injectors are not spraying in four cylinders, thus saving fuel, but the engine must turn at the same speed as before to maintain the car's same speed!



Per http://www.allpar.com/mopar/new-mopar-hemi.html:

"The MDS (“multiple displacement system�) seamlessly alternates between fuel economy in four-cylinder mode, and power in V-8 mode. Owners receive the powerful benefit of the Hemi engine with the fuel economy that they would expect from a less powerful V6 engine. Most test drivers cannot tell the difference.
"The MDS was part of the engine's original design," said Bob Lee, Vice President Powertrain Product Team, Chrysler Group. "This resulted in a cylinder-deactivation system that is elegantly simple and completely integrated into the engine design. The benefits are fewer parts, maximum reliability and lower cost."
This system should triumph where the Cadillac 4-6-8 failed because of the speed of modern electronic controls, the sophistication of the algorithms controlling the systems, and the use of electronic throttle control. The HEMI will be able to transition from eight cylinders to four in 40 milliseconds (0.04 seconds).
The system deactivates the valve lifters. This keeps the valves in four cylinders closed, and there is no combustion. In addition to stopping combustion, energy is not lost by pumping air through these cylinders.
Fuel economy gains go up to 20 percent under various driving conditions, with a 10 percent (or so) aggregate improvement, without any change in customer experience—drivers will receive the benefit without changing their driving habits or losing power.
Don Sherman's article in Automobile noted described a test of the MDS. They found that only four cylinders were used during 17% of the suburban traffic portion of the test, during a full 48% of the freeway test which included "over 70 mph" speeds. Overall, they found that the engine powered down to four cylinders about 40% of the time. Non-enthusiast drivers may experience even more savings. As with most testers (including us), Don was generally unable to detect the changes from four to eight cylinders and back again.
Chrysler engineer Cole wrote: "The modern HEMI always shuts off the same four cylinders. In our duarability test cycle (150,000 customer equivelant miles driven at the 95 percentile, meaning that only 5 percent of our owners are more abusive than our testing), we have not found any adverse wear patterns." (Chrysler PR materials boasted of “over 6.5 million customer-equivalent miles through development and durability testing.�)"

 

Not that this helps (^^ they pretty much covered it all ^^)
I read that the 08's come with an MDS indicator light. It's about time.

 

You were way more kind than I would have been about the MDS operation causing RPM's to drop. (LOL)