[MoparTen]

Friends, I ran tests for fuel economy with the Auto Stick on and then with the auto in Drive with MDS = city and highway. Wow, was I surprised!!!
I had been reading where some were touting the auto stick for economy with the MDS off. I didn't believe it. Here are the results (non scientific of course):

1): Using the auto stick and leaving it engaged in the city showed at least a 10 mpg instant avg over the MDS . The only exception is coasting where they both were about equal.

2): Using the auto stick and leaving it engaged driving on the interstate and other 'highways' again showed the auto Stick had an average (sometimes instant) 10 MPG over the auto with MDS engaged.

I know, I couldn't believe it. I kept testing and grabbing the meter from my son thinking he was fooling me but its true. I found no situation (with the exception of that rare coasting to a stop and that wasn't constant) where the MDS gave better gas mileage.
I did one tank with the MDS and averaged 19 MPG overall. Another tank with the auto stick yielded 27.6 MPG over all.

Unless the Ecometer made by Autometer was consistently incorrect, the auto stick is the way to go. It showed 8 mpg when accelerating to 3000 rpm which was the same as the plain auto (only auto took longer), then (auto stick) dropped to the average of 18 to 88 mpg depending on the load while the auto was always avg 10 mpg lower, same speed, same stretch of road.

Now, why do we have MDS? I'll never use mine again. Can anyone confirm that these observations may be true and somewhat accurate?

Thanks.....

 

[R/TCLASSIC]

so to clarify are you saying it is more economical to shift manually?

 

[MoparTen]

so to clarify are you saying it is more economical to shift manually?

Absolutely, most definitely. And when you get to 4th or 5th leave it (depending on speed). Do not put it in 'Drive' to engage the MDS. Those are my findings...:scratchhead:

 

[walkerheaders]

thats a lot of work compiling that info......thanx for sharing.
I have an R/T auto as well. i am interested to know if hand calculating the MPG at fill up time would produce the same results.
i for one am not familiar with the ecometer you used? what does it hook up to? did your EVIC MPG readout concur with your findings? and did you have to manually shift it all the time in "autostick" mode?

thanx again, i will be curious to try some of this testing.

 

[MoparTen]

thats a lot of work compiling that info......thanx for sharing.
I have an R/T auto as well. i am interested to know if hand calculating the MPG at fill up time would produce the same results.
i for one am not familiar with the ecometer you used? what does it hook up to? did your EVIC MPG readout concur with your findings? and did you have to manually shift it all the time in "autostick" mode?

thanx again, i will be curious to try some of this testing.

The Ecometer (about $75) is an on board diagnostic tool that will track instant mpg, mph, tach, distance traveled, time, etc. A bunch of stuff the Challenger already has.
I bought it to test these posts about driving with the auto stick because I just didn't believe they were getting better gas mileage.

The Ecometer hooks directly into the computer diagnostic plug under the dash below the steering wheel.

Yes, I shifted at about 3000 rpm and when I had reached the speed limit, 35, 45, 55, 65, 70, 75 mph, I moved it to the correct gear. (for instance, in town, you can reach the speed limit at 3000 rpm in 2nd so I put it in 3rd. When I gained, more speed (45 mph), I put it in 4th. At 45, it wouldn't let me put it in 5th. And so on)

I hand calculated the final results at each tankful and the meter was correct. But to watch it getting, say 30 mpg on the interstate in 5th with the auto stick and then shift it into D with MDS and it dropped instantly to 20-21 mpg was mind blowing.
I don't have an EVIC so I tried to be as 'scientific' as I could. I was the last person one could convince to use the autostick, but now I'm a believer.

I hope this helps folks :guiness:

 

[itzrick]

Do you know if you have a tune in the car. I know it comes with a CAI and was wondering if they tune the PCM that way from the factory. I just can't understand why they spent all the money on the MDS engineering if it doesn't work. I thought maybe your results were different because of the CAI and maybe a tune.

 

[MoparTen]

Do you know if you have a tune in the car. I know it comes with a CAI and was wondering if they tune the PCM that way from the factory. I just can't understand why they spent all the money on the MDS engineering if it doesn't work. I thought maybe your results were different because of the CAI and maybe a tune.

I really don't know about a factory tune, the Chrysler brass just grins. I do know the functional hood scoop and CAI give it about 15 HP and when I put the Mopar/Corsa catbacks on, I felt a tremendous difference in power.
The trick was watching the meter, learning shift points (usually about 3000 RPM) and then set her in the correct gear and leave it until circumstances on the road dictate changing it. Very time consuming experiment but I learned a lot.

 

[itzrick]

I have no doubt that you can shift smarter than the tranny in town, just cant see if your at interstate speed on cruise and your squirting into 8 cylinders and another one is only using 4 how it can get better mileage. That's why I was trying to guess about needing the extra gas because of a tune. It's real good info. I have a CAI and tune so I most likely will get what you did. Inquiring minds just want to know.

 

[MoparTen]

I have no doubt that you can shift smarter than the tranny in town, just cant see if your at interstate speed on cruise and your squirting into 8 cylinders and another one is only using 4 how it can get better mileage. That's why I was trying to guess about needing the extra gas because of a tune. It's real good info. I have a CAI and tune so I most likely will get what you did. Inquiring minds just want to know.

I didn't believe it either which is why I did the tests. 4 cylinders should use less gas than 8 cylinders. Not so, the 4 that were working, were sucking in the gas while in 8 cylinder mode, it wasn't using near as much. I guess working smarter than harder??

 

[Wrex]

So what if I have a predator and disabled the MDS feature? Is it still better to use autostick at that point?

 

[R/TCLASSIC]

thats really incredible,i know it always seems to shift at too low a rpm imo,kinda''lugging''the motor and the same downshifting, a friend who has had mercedes say they are the same,just a really weird transmission i guess? i am going to try driving it in manual shift mode for a while(which i like doing anyway). it would be cool to do a youtube video on this,and where do you get an econometer? thanks for your research on this btw!

 

[MoparTen]

So what if I have a predator and disabled the MDS feature? Is it still better to use autostick at that point?

I don't have a predator but I say yes. A lot depends on when and how you shift. I would do it manually rather than use auto.....

 

[MoparTen]

thats really incredible,i know it always seems to shift at too low a rpm imo,kinda''lugging''the motor and the same downshifting, a friend who has had mercedes say they are the same,just a really weird transmission i guess? i am going to try driving it in manual shift mode for a while(which i like doing anyway). it would be cool to do a youtube video on this,and where do you get an econometer? thanks for your research on this btw!

The Ecometer made by Autometer is advertised as a Mopar part. I found mine on ebay. Just mounted it in the car. Hated to mount it on the nice interior but I put mine on the driver's 'windshield post'. (I got tired of holding it).

Another impt tip. In town, country,, roll the throttle to shift quickly about 3000 rpms and then put the auto stick in the highest gear it will go in. If you have to accelerate , say merging on to the Interstate, drop to appropriate gear, shift about 3000rpm and drop to 4th and 5th as soon as possible. I hope this is useful.

 

[HEMI2NV]

on my 07 Ram HEMI i disabled MDS with the tuner and MPG went up so i do believe it. this is part of the reasn i went for the 6.1 over the 5.7 in my Challenger...no MDS

 

[devnulll]

Just curious, what do you mean by saying that you tested MDS in the city?

My understanding is that this technology really only works when driving with constant speed/cruising on a highway...

A factor to consider for your results is also the learning 'habit' of the transmission. The car would learn your driving 'habits' and change gears based on that. I would try resetting it back to factory default - there was a combination with the gas pedal on/off key or something... and testing it again. Maybe you drove it too aggressively during learning and that is affecting your results when on auto, just a thought.

 

[Budriss]

Absolutely, most definitely. And when you get to 4th or 5th leave it (depending on speed). Do not put it in 'Drive' to engage the MDS. Those are my findings...:scratchhead:

Im not entirely convinced by this, 27MPG average (city/highway) using auto-stick feature on your auto trans. Just seems really high compared with what a lot of other people are reporting.


I have a RT 6-speed and take it very easy while commuting. I usually skip shift 1-3-5 and manage average 18.8 -19.0 MPG with about 285 miles/tank.


I calculate my average MPG at the pump, with the trip odometer and the amount of fuel I put in.

 

[runner2go]

So using a meter is one thng (any meter)... but what did the actual math show?
You know, gallons dumped in the tank divided into mileage driven?

I never trust a meter... especially the one built into the car.
They can be pretty accurate, but are darn easy to fool.
Quick acceleration followed by a coast usually make the dash meter look great...
Until you go to the pump and do the math and see the ugly truth.

 

[Budriss]

Im not entirely convinced by this, 27MPG average (city/highway) using auto-stick feature on your auto trans. Just seems really high compared with what a lot of other people are reporting.

I have a RT 6-speed and take it very easy while commuting. I usually skip shift 1-3-5 and manage average 18.8 -19.0 MPG with about 285 miles/tank.

I calculate my average MPG at the pump, with the trip odometer and the amount of fuel I put in.

So using a meter is one thng (any meter)... but what did the actual math show?
You know, gallons dumped in the tank divided into mileage driven?

I never trust a meter... especially the one built into the car.
They can be pretty accurate, but are darn easy to fool.
Quick acceleration followed by a coast usually make the dash meter look great...
Until you go to the pump and do the math and see the ugly truth.

My point exactly

 

[Devil]

I don't know how someone could think running a car without MDS on will save you gas?

It is designed to shut the gas off to 4 of the cylinders when they are not needed.

When doing city driving, it makes little to no difference using MDS, it isn't on long enough to see any difference. I drive through Chicago traffic and average per my calculations between 16-18 mpg. I tried it with Autostick... I got between 13-17 mpg on average.

Going on the highway, where MDS is used best I can get high 20's depending on how eager I am to get somewhere. If very careful, I have gotten low 30's.

At 60 mph, your car only needs approximately 80 hp to maintain that speed. So those extra cylinders are just wasting gas.

 

[MoparTen]

My point exactly

If you had read all the previous posts, you would see that I checked each trip with good old fashion math at the pump.......