HEMI® V8 Has MDS Technology

Get the power and capability you crave with the fuel economy of a less powerful engine that you deserve. Paired together, HEMI® V8 meets MDS technology to create the perfect engine for those power hungry yet budget conscious enthusiasts.

The HEMI® V8 engine now has Variable Valve Timing (VVT) that improves fuel economy in two ways. First, it reduces the engine's pumping work by closing the intake valve later. Second, it increases the expansion process of the combustion event. This allows more work to be transferred to the crankshaft instead of being rejected out of the exhaust port as heat. Essentially, VVT improves engine breathing, which improves engine efficiency and power.

Chrysler’s fuel-saving Multi-Displacement System (MDS) seamlessly alternates between smooth, high-fuel-economy four-cylinder mode when less power is needed, and V8 mode when more power from the new 5.7-litre HEMI® V8 engine is in demand. This optimizes fuel economy when V8 power is not required, without sacrificing vehicle performance or capability. When MDS is operating, it is indicated by a "Fuel Saver" readout on an Electronic Vehicle Information Centre.

An expanded MDS operating range in the new-for-2009 HEMI® V8 will allow customers to realize an even-greater fuel economy benefit. Chrysler estimates that since the inception of MDS in 2005, nearly 379 million litres (100 million gallons) of gasoline have been saved, along with reduced carbon dioxide (CO2) emissions of close to a million metric tons.

In addition to VVT and expanded MDS operating range, the 5.7 L HEMI®'s fuel economy and performance improvements result from an increased compression ratio, an active intake manifold with long runners for low-end torque and short runners for high-rpm power, improved cylinder head port flow efficiency, and reduced restriction exhaust and induction systems.

Numerous other hardware upgrades were implemented to build on the quality, reliability and durability reputation of the HEMI® V8 engine. These include; crankshaft structural upgrades, a dual-mass crankshaft damper, floating pin piston design, valve spring design, and oil pump capacity increase for VVT.

Chrysler engineers will never stop improving this technology and will continue to find better ways to improve this legendary engine.