The engine's greatest disadvantage, at least for truck applications, is its sharp torque curve that peaks at relatively high engine speeds. This characteristic lacks the low end torque favored in applications where towing and hauling needs are frequent and requires operating at higher engine speeds to realize the engine's full performance. On the contrary, the engine produces respectable peak horsepower and torque considering it displaces a mere 345 cubic inches. To help with emissions and address flame propagation concerns inherent of most engines with hemispherical combustion chambers, the 5.7L utilizes a dual spark plug design with a secondary spark plug firing at the start of the engine's power stroke.
The 5.7L Hemi underwent many changes for the 2009 model year, including a higher compression ratio, active intake manifold, variable camshaft timing, and a multi-displacement system (MDS). The active intake runner system allows the engine to utilize short and long runners in the intake manifold. To increase low end performance, the short intake runners are blocked off and air flows through the long intake runners at low engine speeds. At higher engine speeds, the intake manifold opens up the short runners for improved top end performance. The multi-displacement system deactivates cylinders 1, 4, 6, and 7 under low load conditions to improve fuel economy.
5.7L Hemi V-8 Specs
| Engine | Chrysler 5.7L Hemi V-8 | |
| Configuration | 90° pushrod V-8 | |
| Assembly Plant(s) | Saltillo Engine Plant, Ramos Arizpe, Mexico | |
| Applications | 2003 - current Ram 1500/2500/3500 Many Chrysler car/SUV applications - these specifications focus on the Ram truck version |
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| Displacement | 345 CID, 5.7 liters | |
| Firing Order | 1 - 8 - 4 - 3 - 6 - 5 - 7 - 2 | |
| Bore | 3.917 in (99.49 mm) | |
| Stroke | 3.578 in (90.88 mm) | |
| Compression Ratio | 9.6 : 1 (2003 - 2008 model years) 10.5 : 1 (2009+ model years) |
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| Engine Block Material | Cast iron | |
| Cylinder Head Material | Cast aluminum alloy | |
| Aspiration | Naturally aspirated | |
| Ignition | Coil-near-plug, 2 spark plugs per cylinder | |
| Valvetrain | 2 valves per cylinder, OHV pushrod V-8, hydraulic roller lifters, variable valve timing (VVT/VCT, 2009 MY+) | |
| Fuel Injection | Multi port sequential fuel injection | |
| Fuel Requirements | Regular unleaded gasoline (premium fuel recommended, not required) | |
| Oil Capacity | 7.0 qts w/ filter change | |
| Engine Weight | ~ 500 lbs | |
| Horsepower | 2003 - 2008 Ram 1500/2500/3500 | 345 hp @ 5,600 rpm |
| 2009 - 2012 Ram 1500 | 390 hp @ 5,600 rpm | |
| 2009 - current Ram 2500/3500 | 383 hp @ 5,600 rpm | |
| 2013 - current Ram 1500 | 395 hp @ ,5600 rpm | |
| Torque | 2003 - 2008 Ram 1500/2500/3500 | 375 lb-ft @ 4,400 rpm |
| 2009 - 2012 Ram 1500 | 407 lb-ft @ 4,000 rpm | |
| 2009 - current Ram 2500/3500 | 400 lb-ft @ 4,000 rpm | |
| 2013 - current Ram 1500 | 410 lb-ft @ 3,950 rpm | |
| Maximum Engine Speed | 5,800 rpm | |
| Accolades | Ward's 10 Best Engine List 2003, 2004, 2005, 2006, 2007, and 2009 | |
5.7L Hemi V-8 Horsepower and Torque Curves
