So im one of those guys who still wants to suck the most kms for every liter of gas that i use.

I have been messing around with the MDS system in my truck, just to get up around the 17-18 MPG mark. I'm doing about 15 on a good week, and i live in a pretty flat area. Thinking about it if the truck were running off of 4 cylinders i should be doing more than 15 highway!

I installed the MDS light, and it is confirmed working. BUT that MDS system is very particular of when it turns on. The throttle cannot be more than 12% before it cuts out. (measured using my bullydog tuner) Which in turn is not very much at all. At the start of ANY little slope it would cut out.

SO... is there a way to either A) Mess with the throttle to make it less sensitive. or B) Using starscan or something with a laptop, set the parameters for the MDS system to say deactivate at 30% throttle?

It would take some time to determine at what point the 4 cylinders uses just as much gas as when an 8 cylinder does going up a hill. But I know that a 4 cylinder should be able to carry the truck up a very low grade hill, while still maintaining a less MPG usage then being on 8 cyl. Once it hits that point where its just as efficient as using 8 cylinders, it would cut in in 40ms as it states, and you would get the necessary power.

Just a thought, I don't know if its possible, but it got me thinking.

 

might burn up half the motor pretty quick wouldnt it? lol

 

i would not think so...i mean if you go extensive for sure...30% was just a random number...but 12%, as far as i know the other 4 cylinders are cut off after the lifters (Is that true?) so ya i would put a little more strain on the other 4 cylinders, but i would think a hemi can handle it! if you keep it in safe ranges

 

Does the MDS alternate which cylinders it shuts down to even out wear?? Just a thought.

 

i would really doubt messing with it would gain any reasonable amount of km/L
im sure chrysler did extensive testing on the mds system before mass producing it and more than likely had programmed it to the most fuel efficient settings

 

I really think the mds waste gas instead of saves it.

 

I know it does not waste gas. In my truck anyways as it stands, any acceleration I put on it cuts out. The only time its on is with strait even like 0 degrees or better. or downgrade hills. On a hill i can see anywhere from 25-30MPG INSTANT. Thats not a HILL but less that a 10 Degree grade. Anything above that its in the 30-40 range. But the motor is not working pretty much then so its inaccurate. Also add to the fact that the mds really does cut out in the 40 ms as it states. SO under any pressure your back running 8 cyl anyways.

I do agree however that MDS is useless in the city or on really hilly and turning highways. BUT here in alberta i would call our "hills" more of a grade so it does help. It would help even more if we could make it so it does not cut out so quick. I would that that i could see closer to 20 highway if that were to happen.

 

I dont know its not really a hemi in 4cylinder mode more like an overweight neon.

 

thats what i think.. except its all the time Lol. 4 cylinders to move this big behind truck an not waste gas when 8 cylinders could do it with ease.. i'm not trying to start a war or anything. or It might just be my mds in my truck

 

i know the f-150's get worse gas mileage with the smaller v8 while the bigger triton v8 in the exact same truck gets better mileage