Locked out MDS today, OMG, this truck is Amazing!

[RVGuy]

I heard this as well, and the reason for minimal wear was attributed to the design the used which was to take in fuel wait until compression spark plug ignites after that the valves stay closed keeping the pressured up cylinder acting like a spring. I don't believe other manufacturers do this.

It also fires the inactive cylinders if they're off for a specified length of time to keep them from loosing temperature compared to the active cylinders. I think GM's system does this now too but they didn't before.

 

[OCDTech]

It also fires the inactive cylinders if they're off for a specified length of time to keep them from loosing temperature compared to the active cylinders. I think GM's system does this now too but they didn't before.

Did not know this, it pokes holes in my theory of the cooler cylinders being next to hot cylinders adding to the stress on the manifolds breaking the bolts. hmmmm

Thank you.

 

[Octane]

Those four pressurized cylinders acting as a spring keeps the engine smoother and supposedly vibration free.

 

[OCDTech]

Those four pressurized cylinders acting as a spring keeps the engine smoother and supposedly vibration free.

The vibration is definitely there. But i don't believe its from and unbalance, its from 4 cylinders trying to push a heavy truck in 8th gear at 55 mph.

 

[chrisbh17]

I don't think it causes wear on the cylinders, but the extra parts in the lifters could technically cause durability issues with the lifters themselves. Our trucks have cam or lifter issues even on non mds engines or cylinders so it's probably a non issue anyway.

Sent from my Pixel 3 XL using Tapatalk

 

[OCDTech]

What i do is every now and then i will let them work, (mile or so). Just to keep them exercised. I never use the MDS.

 

[RVGuy]

What i do is every now and then i will let them work, (mile or so). Just to keep them exercised. I never use the MDS.

Every once in awhile I'll let it turn on, then I'm reminded of the noise, vibrations, and delayed throttle response and I turn it back off.

I usually run in tow/haul and the manual gear selector, and I still get better mpg than 90% of people seem to get.

 

[OCDTech]

Every once in awhile I'll let it turn on, then I'm reminded of the noise, vibrations, and delayed throttle response and I turn it back off.

I usually run in tow/haul and the manual gear selector, and I still get better mpg than 90% of people seem to get.

This exactly.

 

[OCDTech]

I never look at my mileage on the EVIC anymore so its running a long average. I know its a little optimistic but it was on 23.5 when i looked at it the other day.

 

[chrisbh17]

TBH I only find MDS "disagreeable" when driving around town. I feel like it comes on too early and takes too long to deactivate at lower speeds (40mph and under).

On the highway, I really dont mind it. It seems to come out of MDS much quicker at 60mph+.

 

[RVGuy]

TBH I only find MDS "disagreeable" when driving around town. I feel like it comes on too early and takes too long to deactivate at lower speeds (40mph and under).

On the highway, I really dont mind it. It seems to come out of MDS much quicker at 60mph+.

Agreed. I can't tell when/if it comes on at highway speeds. I suspect it doesn't actually come on for me on the highway even when it's left on as highway speed here is around 75mph. Any slower and people start almost rear ending you.

 

[RVGuy]

I never look at my mileage on the EVIC anymore so its running a long average. I know its a little optimistic but it was on 23.5 when i looked at it the other day.

I hand calculate, I'm currently at 18mpg on the EVIC, last fill up EVIC said 17mpg and hand said 16mpg so it's not far off. That was driving into the mountains with a bad headwind so I can live with that mileage.

 

[OCDTech]

Oh me to, anything better than 17 is good with me.

 

[dhay13]

My EVIC is usually about .5 over my hand calculated. Be curious to see how this tank is. Mostly highway and EVIC is reading about 15.8 right now after 200 miles on this tank. I'm averaging about 11.9 hand calculated since I got my truck (5000 miles ago). That is about 60-70% in town driving.

 

[seabrook]

This exactly.

I do this too but I also turn off traction control- It seems to give it better throttle response

 

[OCDTech]

I do this too but I also turn off traction control- It seems to give it better throttle response

I will have to try that, thanks!

 

[RVGuy]

Got my best tank for the past couple years today. 12.3L/100km which is 19.1mpg
That was mostly tow/haul as I was driving in the mountains. Kind of wonder what it would have been with MDS on, but I'm pretty darned happy to get that out of a truck with 160k miles on it.
(My odometer is wrong so don't pay attention to what the mileage on the app says, I got tired of doing the math every fill up)

 

[madtrucker2016]

use tow/haul mode ... simple

that dont mess the tranny up? tow haul all the time

 

[kurek]

that dont mess the tranny up? tow haul all the time

Tow/haul does not disable mds on 1500s, this has been beat to death a number of times.

It won't damage your transmission to use tow/haul all the time but you will get worse mileage. Tow/haul changes the shift pattern a bit but it also increases line pressure which forces the pump to work harder all the time. The pump doesn't mind but it costs you fuel to generate that pressure and it puts more wear on the fluid in everyday driving by applying more heat on a constant basis even when there is no friction wear occurring.

 

[CheechDogg.0n37s]

Aphaobd will perminately turn it off with settings. Along with other good **** too. Like turning on the drl tune the trans for better shifts...

Blue Mule

Wait ... how do you turn it off with AlfaOBD ?... I thought only with a tuner you could ... I see nothing in the settings to turn it off in AlfaOBD ...