I have it on David, thanks though.

 

Actually, I think cruise control is not as good as the foot for staying in MDS. With cruise control on, it will keep your speed constant. Which means it will constantly throttle up and kick out of MDS to maintain that speed when going over slight hills, etc. Will also downshift going downhill to maintain set speed, which again, will tend to kick it out. To get the best fuel economy (and stay in MDS the longest) it is best to keep engine load (and not speed) constant. This can only be done with the foot, allowing yourself to lose some speed when climbing and accellerating on the downhill, etc. Once you really get in tune with what you are feeling (a muffler swap helps), it's amazing how long you can run on four cyl if you really try.

 

I live in area with a slight change in elevation..so for the hour trip to yorkton no MDS but on the down sloppe home all the way. the mpg changes about 4....its a 4 savings in the end so that make me happy. Mine sharted MDS right off the lot. I also made a 400 km trip that day.

 

OPERATION


<A xmlns="http://www.w3.org/1999/xhtml">
The Multiple Displacement System (MDS) provides cylinder deactivation during steady speed, low acceleration and shallow grade climbing conditions to increase fuel economy. Both four and eight cylinder configurations have even firing intervals providesmooth operation. Two cylinders on each bank are active when the engine is in four-cylinder mode – every other cylinder in the firing order. All of the cylinders that are deactivated have unique hydraulic valve lifters that collapse when deactivated to prevent the valves from opening. Engine oil pressure is used to activate and deactivate the valves. It is delivered through special oil passages drilled into the cylinder block. Solenoid valves control the flow. When activated, pressurized oil pushes a latching pin on each valve lifter, which then becomes a “lost motion” link. Its base follows the camshaft, but its top remains stationary, held in place against the pushrod by light spring pressure but unable to move because of the much higher force of the valve spring.


NOTE: It is critical to use the recommended oil viscosity in 5.7L engines that use MDS.
Deactivation occurs during the compression stroke of each cylinder, after air and fuel enter the cylinder. Ignition then occurs, but the combustion products remain trapped in the cylinder under high pressure, because the valves no longer open. No air enters or leaves. During subsequent piston strokes, this high-pressure gas is repeatedly compressed and expanded like an air spring, but fuel is not injected.

 

Unfortuantely, I bought an early build '09 Ram without the Fuel Saver indicator. Could one of you with the indicator (safely) take a pic of it in action? When I went for a test drive, my salesman "pointed it out" and I assumed I was just looking in the wrong place. Now I realize it was never there.

 

I would have stopped payment on the downpayment and then take him for a ride and ask about where that light was? You have a case for a new truck. I would get one f g lying salesman do not help sales of vehicles as don't un educated. I worked at Chrysler for 16 years mainly on the line first 8 years then in repairs in the front end after they are built so you have to know all about the vehicle, on the launch team, on the ISO team I had a great last 8 years then I was paralyzed but I loved going and the salesmen would try to lie to me about something I would catch him in it and he would say well it was there last year...I would catch him in number 2,,, third ly I talked to Salesmanager about the 3 lies I was told and man were they ever happy to throw in oil changes, undercoating, rustproofing window tint whatever you ask for and even though they say no commission on employee sales why do they work so hard for you? Why lie knowing I might be educated more than he realizes. They should all be fired makes a bad name for Chrysler and right now they don't need it.

 

Just took my first road trip in my RCSB with 3.92's. Fuel saver comes on often as long as I am under 55-60 mph. Even on a flat road, no wind, it never comes on when over 60-65 mph unless going down an incline, and pressure on the gas pedal is released. Overall, the computer gas mileage was 20.1 mpg for the whole trip including around town at the destination. Pretty pleased with that, but think if the MDS was more aggressive at highway cruising speeds, it could have been better. Only 1600 miles on the truck, so maybe as it breaks in more, the fuel saver will come on more @ above 60 mph.

 

Sweet. Could you snap a quick pic of it next time it's on? Thanks!

 

I'm not too broken up about my truck not having it- I'm just going to enjoy driving it and not worry about it. It's not the end of the world and I'd probably just end up turning it off anyway.

The only thing I'll probably do to the gauge cluster is work out a way to put some tint film inside it over the high-beam indicator light. It's way too bright at night, especially with the interior lights dimmed.

 

An easy way to know when the MDS is on is to replace your muffler with a more aggressive one. With the Mufflex 14 I have, you can hear the MDS kick on and off.