Dodge’s Multi-Displacement System (MDS) in its V8 engines improves fuel economy but negatively affects performance.
If you want your Ram 1500 running at full power, you’ll need to turn off MDS.
You can turn off MDS in a Ram 1500 temporarily and permanently. To disable MDS temporarily, shift into the highest gear. To do so permanently, you must either use a tuner or upgrade to a performance camshaft.
What Is MDS in the Ram 1500?
MDS (Multi-Displacement System) is Chrysler’s form of engine variable displacement.
When the vehicle’s throttle is closed or steady, it shuts off four of the eight cylinders in a V8 engine.
MDS activates when you’re traveling at a constant speed, decreasing emissions and improving fuel economy by up to 20%.
Does MDS Affect Performance?
In most modern cars, as long as the MDS works properly, drops in performance are minor, and the effects are negligible.
However, with other vehicles, previous iterations of the MDS caused a more obvious drop in performance.
The biggest issues with older MDS vehicles are they do not shift smoothly and lose power when driving at a constant speed.
Drivers also complain they sometimes hear the MDS turning on and off, which can be distracting.
Additionally, issues with MDS become more apparent after other modifications have been made to the vehicle.
2 Methods to Turn Off MDS Permanently in a Ram 1500
If you want to increase your Ram’s performance by turning the MDS off permanently, you have a few options for disabling the system.
1. Get a Performance Camshaft
In most cases, installing a performance camshaft will disable MDS.
Moreover, a performance camshaft allows more air into your engine.
Additional air means more fuel is injected, giving you better performance.
Disabling MDS will give you finer performance, and adding a new camshaft can really improve how your Ram 1500 drives.
2. Use a Tuner
A tuner is a device you can use to change some of the factory settings in your truck’s computer.
Although a tuner may seem intimidating at first, it’s actually quite simple.
There are thirteen easy steps to turn off MDS with a Diablo tuner.
If you have a different tuner, the steps may be slightly different.
Generally speaking, however, disabling MDS with a tuner will be pretty much the same no matter which tuner you have.
Steps to turn off MDS with a Diablo tuner:
- Turn on your car’s engine
- Plug your tuner into your truck’s OBD port, which you will find above the brake and gas pedals
- Turn on your tuner
- Navigate to the “Performance” section of your tuner
- Choose “Diablo Tunes”
- Select your fuel (Octane rating)
- Choose “Modify Tune”
- Select “Modify Parameters”
- Go to “MDS”
- Choose “Off”
- Hit the back button
- Choose “Install Tune”
- Follow the prompts on the screen.
After completing these steps, your tuner will tell you that it has completed the modifications and that you can go ahead and drive your truck.
MDS should now be disabled.
How to Disable MDS Temporarily?
If you want to disable MDS just some of the time instead of disabling it completely, you need to put your Ram in the highest gear.
You must first shift into DRIVE to do this in a Ram 1500 with a console shifter.
Then, move your shifter to the left, putting it into manual shift mode.
Next, keep pushing the shifter to the right until you reach the highest gear.
If you have a Ram 1500 with a dial shifter, you need to push the negative shift button on your steering wheel to put your truck in shift mode.
Afterward, press the positive shift button until you reach the highest gear.
Or, if your shifter is next to your steering wheel, you need to press the negative button on the shifter to put the truck in shift mode.
Then, press the positive button until you reach the highest gear.
MDS will be disabled for the remainder of your drive.
Which Cylinders Deactivate When MDS Turns On?
When MDS activates, cylinders 1, 4, 6, and 7 will turn off in that order.
Do All Hemis Have MDS?
Not all Hemis have MDS; however, the system has been increasingly popular since 2005, with Chrysler adding it to the Ram 1500 in 2006.
Many automatic vehicles produced in the last 15 years have MDS. Vehicles with manual transmissions do not have the system.
Should I Turn Off MDS?
Turning off MDS depends on your personal preferences.
If you want better fuel economy, leave the system on.
Some drivers, however, can not stand MDS, even if they benefit from improved gas mileage.
The main complaints are that it decreases the power in the engine and makes the ride less smooth.
So, if you prize a powerful and smooth engine, you should turn off MDS.
If you want to save on gas while reducing emissions, keep MDS activated.
Does Turning Off MDS Actually Save Gas?
Whether MDS activates and saves you gas depends on where you’re driving.
If you’re driving in the city, MDS will not activate because your throttle is not running at a constant position.
However, MDS certainly improves fuel economy when it comes to highway driving.
It may not save you 20% as it claims to, as you will only get the full benefit if you drive at a constant speed the entire time.
For the most part, depending on driving conditions, your truck’s fuel economy will improve by around 5% to 15% when on the highway.
MDS is an automobile displacement system for Chrysler/Dodge V8 engines that improves fuel efficiency and decreases vehicle emissions.
While many drivers don’t mind the system, some prefer their vehicles to operate at maximum performance levels.
You can turn off MDS in your Ram 1500; however, disabling it will negatively affect your fuel economy.
To disable the system temporarily, shift into the highest gear.
To deactivate the system entirely, you must use a tuner or upgrade to a performance camshaft.
Table of Contents
- What Is MDS in the Ram 1500?
- Does MDS Affect Performance?
- 2 Methods to Turn Off MDS Permanently in a Ram 1500
- How to Disable MDS Temporarily?
- Which Cylinders Deactivate When MDS Turns On?
- Do All Hemis Have MDS?
- Should I Turn Off MDS?