If you've ever stood on a used car lot looking at a Ram 1500 or a high-mileage Charger, you've probably asked the salesperson: how much horsepower is a 5.7 hemi? They usually give you a round number. 390. Maybe 395. But honestly, the answer is a moving target because Chrysler has been tweaking this engine since it hit the scene in 2003. It's not just one number. It’s a legacy of iron and aluminum that has powered everything from work trucks to police cruisers.
The 5.7-liter Hemi is the quintessential American V8 of the modern era. It’s loud. It’s reliable. It’s got that specific "Hemi grunt" that people pay a premium for. But the actual output varies wildly depending on whether you're looking at an early 2000s Durango or a brand-new eTorque-equipped Ram.
The Evolution of the 5.7 Hemi Horsepower
When the 5.7 Hemi first launched in the 2003 Dodge Ram, it was a revelation. It replaced the aging 5.9-liter Magnum V8, which was basically a boat anchor by comparison. That first generation of the modern Hemi pushed out roughly 345 horsepower and 375 lb-ft of torque. For the time, that was huge. You have to remember that back then, Ford’s 5.4-liter Triton was struggling to keep up.
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Then came 2009. This was the turning point.
Engineers introduced "Eagle" heads and Variable Valve Timing (VVT). This wasn't just a minor update; it was a total overhaul of the top end. Suddenly, the how much horsepower is a 5.7 hemi question got a lot more exciting. Power jumped into the 360 to 395 horsepower range. If you buy a Hemi today, you’re essentially driving a refined version of that 2009 "Eagle" architecture.
Why the Numbers Look Different on Every Spec Sheet
You’ll see 360 hp for a Jeep Grand Cherokee and then 395 hp for a Ram 1500. Same engine? Mostly. The difference usually comes down to the intake manifold design and the exhaust routing. Trucks have more engine bay room. They can breathe better. Large, sweeping intake runners allow the air to flow more freely, which is why the Ram usually wears the crown for the highest stock horsepower ratings in the 5.7 family.
In the cars—the Dodge Challenger and Charger—the numbers usually hover around 370 to 375 horsepower. It’s plenty. It’ll chirp the tires in third gear if you aren't careful. But it’s lower than the truck because the packaging is tighter. Heat soak is a real thing in those car bays, and the tuning reflects that.
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Horsepower vs. Torque: What Actually Moves You
Horsepower sells cars. Torque wins races. Or, more accurately, torque pulls trailers. While we obsess over how much horsepower is a 5.7 hemi has, the 410 lb-ft of torque is the reason people keep buying them.
The Hemi is a pushrod engine. Old school. It doesn't need to scream at 7,000 RPM to make power. Most of that torque is available right down low. If you’re towing a 7,000-pound camper up a grade in Colorado, you don't care about the peak horsepower at redline. You care about the grunt at 2,500 RPM. The 5.7 delivers that consistently.
Real World Performance and The eTorque Factor
Lately, Ram has been adding a "mild-hybrid" system called eTorque. People get confused here. They think it adds 100 horsepower. It doesn’t. The gas engine still makes the same 395 horsepower. The eTorque system is basically a fancy belt-driven generator that adds a burst of torque (up to 130 lb-ft) for a split second to help the truck get moving from a dead stop.
It makes the truck feel faster. It makes the stop-start system feel less like a seizure and more like a smooth transition. But on a dyno? The peak horsepower remains unchanged. It’s still the same 5.7 Hemi you know and love.
The "Hemi Tick" and Power Loss
We can't talk about Hemi power without talking about the elephant in the room: the Hemi Tick. It's a localized legend in mechanic shops. Usually, it's just a broken exhaust manifold bolt. No big deal. But sometimes, it’s a lifter failure that starts eating the camshaft.
When a cam lobe gets worn down, your valve lift decreases. Less air gets in. Less exhaust gets out. If your Hemi sounds like a sewing machine, you’re probably not making the factory-rated horsepower anymore. Owners who ignore the tick often find their "395 hp" truck feels like it’s down to 300. Maintenance matters. Use a high-quality synthetic oil and change it every 5,000 miles, regardless of what the "oil life monitor" says. Your camshaft will thank you.
Modifying the 5.7 for More Power
So, you have your how much horsepower is a 5.7 hemi answer, but you want more? You aren't alone. The aftermarket for this engine is massive.
- Cold Air Intakes: Mostly for noise. You might gain 5-8 hp, but you’ll hear that Hemi growl much clearer.
- Long Tube Headers: This is where the real power is hidden. The factory manifolds are restrictive. Swapping to headers can net you 20-30 hp easily.
- Custom Tuning: The factory tune is conservative. A professional tuner can sharpen the throttle response and squeeze another 15 hp out of a stock engine by optimizing fuel and spark curves.
- Cam Swaps: This is the big boy move. Putting a "Comp Cam" or a "Texas Speed" cam in a 5.7 can push you well over the 450 horsepower mark. It changes the soul of the car. It’ll chop at idle and pull like a freight train to the redline.
Comparing the 5.7 to the 6.4 (392)
People often wonder if they should spring for the 6.4-liter Hemi (the 392). The 5.7 is the "sensible" V8. The 6.4 is the "hold my beer" V8. While the 5.7 sits around 395 hp, the 6.4 jumps up to 485 horsepower in the cars.
Is the 6.4 better? For speed, yes. For longevity? That’s debatable. The 5.7 is a simpler, more over-engineered block for daily driving. It handles high mileage better than its bigger brother. If you're building a 300,000-mile truck, the 5.7 is the one you want.
Environmental Impact and the End of an Era
It’s no secret that the Hemi is a dinosaur. Stellantis is phasing it out in favor of the "Hurricane" inline-six twin-turbo. Why? Because while we love the 5.7 Hemi horsepower, the government doesn't love the fuel economy. The 5.7 is thirsty. Expect 13-15 mpg in the city if you have a heavy foot.
The new Hurricane engines actually make more horsepower than the 5.7, but they don't have the V8 soul. They don't have the rumble. We are living in the sunset years of the naturally aspirated V8. If you want one, now is the time to get it before they become museum pieces.
What to Look for When Buying Used
If you're hunting for a used Hemi, check the idle hours. High idle hours are a killer for these engines because the oil pressure is lower at idle, which starves the lifters. A truck with 100,000 highway miles is often in better shape than a city truck with 50,000 miles and 2,000 idle hours.
Listen for that tick.
Check the water pump.
If the engine is clean and has been fed a steady diet of 5W-20 (or 0W-20 in newer models), it will easily provide that 390+ horsepower for a decade or more.
Actionable Steps for Hemi Owners
To keep your 5.7 Hemi running at its peak rated horsepower, follow these specific steps:
- Switch to a high-moly oil. Many Hemi enthusiasts swear by Red Line 5W-30 (yes, slightly heavier than stock) to help prevent the dreaded lifter tick. The molybdenum helps coat the needle bearings in the lifters.
- Clean your throttle body. Every 30,000 miles, take ten minutes to wipe out the carbon buildup. It restores the snappy throttle response the Hemi is known for.
- Check your exhaust manifold bolts. If you hear a "tick" that goes away once the engine warms up, it’s an exhaust leak. Fix it early before the warping gets worse and robs you of backpressure and performance.
- Use 89 Octane. While the 5.7 can run on 87, Chrysler officially recommends 89 octane for "optimum performance." The knock sensors will pull timing on cheap gas, which lowers your actual horsepower.
The 5.7 Hemi isn't just a number on a brochure. It’s a workhorse that has defined a generation of American driving. Whether it's the 345 hp of the early years or the 395 hp of the modern Ram, it remains one of the most versatile engines ever built. Know your numbers, maintain the hardware, and enjoy the sound while we still can.