So... One of the reasons i liked this truck is i was told it had the cylender deactivation option, but after a few weeks i have yet to see it or know if it is working or not. I have the 2008 Dodge Ram 2500 Heavy Duty 5.7 Hemi Larame. Should i be seeing something on my guage cluster or what?

 

2500s don't have MSD, only the half-tons.

 

Well that sucks! Why is that? I also see that no maintanace has been done according to log book and it has 54000km on it. i bought it off lease and had to fight to get the dings out of it also, now i think i have to complain a bit! i believe it should at least have the plugs changed at this point.

 

I suspect the 2500s are just too heavy for MDS to be effective. Unless you have in writing from the dealer the truck has MDS, you might as well let that one go. Even if they wrote it for you, I doubt they could make it work.

NO maintenance?! Plugs aren't necessary just yet, probably. You can probably let them go to 70km or 80km. I'd change ALL the fluids, though. The tranny's about due. The diff is overdue.

 

I think even the 1500s are too heavy for MDS and it doesn't work nearly as good as they claim. I have it turned off right now and noticed no decrease in MPG. When my truck went into 4 cyl mode the revs got higher. A 4 cylinder engine has to work harder to keep a 5000+ pound truck moving.

 

lyin Sons of a Beachball, 2 cheeseburger eatin office weinies. I like all 8 cyls too, and am curious if the MDS actually gets you in the 20 MPG range, is that how teach pulls it off?

 

Before I installed my 180 t-stat I could get 20 on the highway with MDS off.
I noticed a decrease in mileage with the 180 t-stat and I'm considering putting the 203 back in.

 

Wow thats real good as my old girls best was 18.8 but our gallons are bigger up here. Obviously the never models are more fuel efficient.

 

The newer ones are always more fuel efficient. Look at trucks in the 90's: Gas hogs and didn't even come close to the power ours have these days.

 

I'm kinda in the camp that the 1500s really shouldn't have it either, I mean it's a full size truck, C'mon!!!

But yeah, patbee, I believe you may be the first person on the planet who was actually lied to by a car dealer... LMAO!!!
You DO NOT have MDS. MDS is found in ALL 1500s, '06 and newer, EXCEPT Mega Rams, but not found in ANY 2500 series trucks.

and Blake, you should see a slight DECREASE in fuel economy with a 180* thermostat. Perfectly normal as it causes the PCM to richen the A/F mix. Pluses of a rich mix is if you have any mods that would cause a leaner than stock ratio like a free flowing exhaust/CAI/Headers and/or a tuner that advances timing it will bring the A/F back closer to stock settings as well as a slight increase in power. Down side is a richer mix isn't an entirely good thing if you are running bone stock and don't need it AND a slight decrease in fuel economy.