Which Mopar engines come with MDS?
In Mopar’s lineup, MDS (Multi-Displacement System) is used on select V8 engines to improve highway fuel economy by temporarily deactivating four cylinders. The engines that come with MDS are the 5.7-liter Hemi V8 and the 6.4-liter Hemi V8. Other Mopar engines generally do not include MDS.
What MDS is and how it works
MDS, short for Multi-Displacement System or Active Fuel Management, is Chrysler’s cylinder deactivation technology. It temporarily shuts down four cylinders in the V8 when cruising under light load, allowing the engine to run on two banked cylinders for better fuel efficiency. When more power is needed, the system seamlessly reactivates the cylinders. Most drivers experience this as a smooth transition, though some may notice a brief change in engine sound or responsiveness during transitions at low throttle.
Engines that offer MDS
Below are the Mopar engines that have shipped with MDS across model years. Availability can vary by model, trim, and market, and some high-performance configurations may bypass MDS to prioritize power.
- 5.7L Hemi V8 — used across Ram 1500, Dodge Charger/Challenger, Jeep Grand Cherokee, and related vehicles. MDS deactivates four cylinders during light-load cruising to save fuel.
- 6.4L Hemi V8 — used in performance models such as the Challenger R/T Scat Pack and Charger Scat Pack, among others. MDS is available to improve highway efficiency, though some performance-focused setups may not rely on it.
The 6.2L supercharged Hemi (Hellcat) and current diesel/Mercury-based Mopar engines generally do not include MDS, as their design focuses on maximum power or diesel efficiency strategies rather than cylinder deactivation. The 3.6L Pentastar V6 and EcoDiesel do not rely on MDS for fuel savings in standard configurations.
Notes for owners and potential buyers
When considering a vehicle with MDS, expect that the system will automatically engage during steady cruising and disengage when you demand more power, such as during acceleration. Modern implementations are designed to be transparent, but some drivers notice subtle changes in engine tone or torque delivery during transitions. Regular maintenance, including timely oil changes and spark plug service (where applicable), helps ensure MDS operates smoothly.
Model-specific availability can vary by year and configuration; always verify with the dealer or official brochure for the exact vehicle you are considering.
Summary
MDS is primarily associated with the 5.7L Hemi V8 and the 6.4L Hemi V8 in Mopar’s current and recent lineups. These engines use cylinder deactivation to conserve fuel during light-load driving. Other Mopar engines — notably the 3.6L Pentastar V6 and EcoDiesel — do not include MDS, and high-performance variants like the Hellcat typically omit it to maximize power.
As automotive technology evolves, availability of MDS can vary by model year and regional market. For the most up-to-date information, consult the latest brochures or a Mopar dealer.
