Originally Posted by MattE71

Wow...the truck is much nicer to drive with that MDS shut down! Especially since I am running Magnaflow exhaust. One thing that I did notice is how much my turn signal / indicator slowed down after installing the 3865. That being said, just a couple questions...

If I am in economy or any other mode for that matter and I want to tow my boat, which is very heavy but a short distance to where I need to go, should I always reprogram to the tow mode with the 3865? This might be inconvenient, if I was in a hurry, or can I tow in any mode? I do understand that if I am in economy mode, I am not going to do well with my mpg. Do I always use the tow / haul button like I normally would anyway (like if the truck was stock) but with the 3865 installed?

Thanks!

Originally Posted by MDSBigPaPa

First, turn signal thing - my truck does that whenever the speedo is changed or viewed. It's the way Dodge resets the PCM in some models. It will return to normal in about 10-20 minutes.

Second, You should NOT tow/haul more than 1500 lbs unless you're tuned to tow AND have 91 or better octane in the tank and YES use the tow/haul button. Pre-detonation (aka pinging) can kill your motor. You could always revert to STOCK, with Tow/haul button engaged, if you don't have 91 or better octane when towing the short distance.

Originally Posted by MattE71

Thanks for the reply! So what happen's if I have 89 octane and the tank is full and I need to hook up my boat? Is there some grey areas to this, would this be a problem? My other question is the fuel economy mode, what is the recommended octane to run? If a poll was taken, I wonder what most guy's have their setting's at?

Thanks again!

Originally Posted by MDSBigPaPa

No problem!

With 89 octane and towing a heavy boat, even in tow program, you may have excessive pinging which can severely damage your motor. How "short" is the short distance you'll be towing? You could test by towing your boat while being careful to listen for any pinging. If you do hear pinging, STOP and retune to STOCK if you have less than 91 octane in the tank.

Economy (Mileage XS) tune is programmed for use of 87 octane.

I get my best mileage with 91 Perf Tune and 93 octane. It takes less throttle to move my heavy rig therefore saving fuel.

Originally Posted by MattE71

95% of the time I would be towing about 4 miles. Luckily we are very close to the ocean! When I first hooked on to the boat, I was running 87 octane with the truck stock and there wasn't any pinging. I had a 98 Dakota with the 5.2L and that thing use to ping like crazy with the 87!

Originally Posted by 06ramquad

i just got a sc 3865 for my 06 1500 5.7. the thing is very confusing to me.when i first got it this morning, i registered and checked for updates.i then proceeded to install the 91 octane tune. I then wanted to disable the mds but could not find it in the menu anywhere.so i updated the sc3865 again and then i found the mds disable function and a bunch of other things.(nice)! anyway,i told it to disable the mds and i am not sure but i think it took off the 91 tune. can anyone tell me how to install the 91 tune AND disable the mds? please help!! thank you!!

Originally Posted by MattE71

I picked mine up last weekend. Tune for the 91 and then go to the advanced settings...I think that's how I did it. I can't remember if you have to do that by programming it twice or not, once for the 91 and then again for the MDS? This is making me question what I just did?! All I can say is....what a difference having the MDS turned off! It's worth buying for that alone. I have Magnaflow cat back exhaust which made the MDS even worse.