Comparing 6.4 Hemi VS 5.7 Hemi Engines – The Ultimate Best?

Two of the insanely popular third-generation engines are what we will be comparing today. From the title you’ve already guessed, it’s a showdown between 6.4 hemi vs 5.7 hemi V8 gasoline engines.

Both were built by Chrysler. And one of the sole reasons people know these so well is their hemispherical combustion chamber. However, at the moment, 5.7 engine as well as 6.4 hemi engine, none are wholly hemispherical.

Now if you are not an Automotive matter person who likes to have every single update of what’s going on in the industry and which engine or maybe some other part is making hype at the moment, then before making a purchase, you’d surely prioritize weighing your options up and then make a decision. And today’s comparison is going to help you there. Hopefully!

6.4 Hemi VS 5.7 Hemi Engines

Comparing 6.4 Hemi VS 5.7 Hemi Engines One by One.

Let’s get through each of them individually first. And then we’ll shortly focus on the comparison points in a segment afterward. You Ready?

The Hemi 5.7 Engine – Noteworthy Reliability, Best Combustion Efficiency & Known To Last Long.

Replacing the 5.9L Magnum, in 2003 5.7 engine became first one to start Chrysler’s 3rd gen engine mission smooth. It was made from scratch and came with a cast-iron cylinder block, a deep skirt design, a 90-degree angle included cylinder banks, and bearing support for crankshaft with 4 bolts.

In 2009, the engine modified wide ring included pistons and put smaller ones instead. So that less inertia could be possible.

5.7 hemi engine provides an amazing 345 to 410 horsepower. And also, the torque is around 375-410 ft-lb. Now shall we discuss a bit about why you should or not get this one.

Why You Should Get 5.7 Hemi Engine:

  • If we compare the 5.7 vs 6.4 hemi reliability factor, the 5.7 engine is a bit ahead with no major design flaws going on. That’s why we consider it a reliable one overall.
  • Compared to any other V8 engine, the combustion efficiency of 5.7 is the best.
  • A well marinated and regularly taken care of hemi 5.7 engine will last you a pretty long time. This should be at least 250-300 thousand miles, which is pretty long. However, keep in mind, you cannot excuse yourself from proper maintenance.
  • The 5.7L hemi is revised and modified to be better environmentally friendly along with its efficiency scores being great.

Why You Should Not Get 5.7 Hemi Engine:

  • For towing and hauling purposes, it’s not the very best. Because there’s some lacking with it about the low-end torque specifically. Optimum engine performance should be considered for improvement.
  • Something in its MDS system makes the valvetrain cause a weird ticking sound. And that’s not true for every 5.7 engine user however quite a few. However, there’s no effect from the sound whatsoever, it’s just a bit annoying.
  • Oil-sensitive MDS can be a bit of a chore to handle sometimes. You cannot use anything less than what is recommended as oil for it.
  • There are 16 spark plugs that need a replacement quite frequently. Almost after every 30 thousand miles. And it’s a bit expensive for some people.

The Hemi 6.4 Engine – Better Low Range Torque, Great Horsepower & Smooth Temperature Consistency.

It was introduced first in 2005 and being a production version, there was a lot of hype for it because of the fabulous towing and hauling suitability it offered. This one also comes with cast iron built and a deep skirt design.

There’s the cylinder block with a 90-degree angle as well and forged steel-made crankshaft was also featured in THIS engine. With the flexibility of spraying oil on piston bottoms with added cooling jets, this engine was loved for its fabulous combustion heat reduction capability.

The engine blocks of both 5.7 and 6.4 is the same one. However, the bore diameter and store length are different.

Why You Should Get 6.4 Hemi Engine:

  • In terms of 6.4 hemi vs 5.7 hemi reliability, the ram version of 6.4 Hemi is also a reliable crate engine.
  • The 6.4 hemi horsepower is impressive and better than the 5.7 hemi.
  • At a low range, the torque of 6.4 is more and it’s at low end around 70 lb.-ft.
  • It can maintain the combustion chamber’s temperature consistently because of featuring piston cooling jets.

Why You Should Not Get 6.4 Hemi Engine?

  • One of the very common issues or complaints about this engine is that it faces MDS solenoid failures. And so, you might experience rough engine running.
  • This one also has that ticking noise issue. Yes, here also sound comes from the valvetrain and there’s no performance drop due to it.
  • One of the common ram 6.4 hemi problems is having a downshift of engine. It goes to 1st gear from 2nd whenever you have heavy loads.

Summarizing The Whole Thing into Comparison Notes.

The first spot where there’s a difference is stroke length. With a longer stroke, the 6.4 engine will be able to provide you better power when compared to 5.7 hemi. But then again, in terms of engine displacement, the hemi 5.7 vs 6.4 fuel economy also gets involved.

Here also you get better results with the 392 cubic inches engine displacement offered 6.4 hemi. While the other one gives around 345 cubic inches, which is not drastically less.

The Hemi 6.4 engine also delivers a higher compression ratio to provide better combustion chamber efficiency. But then again, it’s not dramatically more than the 5.7 engine. Both of the engines are pretty heavyweight, by the way. It’s one of the common disadvantages with both of the hemi engines. 6.4 engine is slightly less weighted than 5.7 hemi.

The 6.4 hemi also has higher horsepower and enough torque at low RPM. While 5.7 engine does not produce enough torque at the low end.

Clearly, we can tell the obvious winner between both of these engines. However, such a comparison does not make any one engine extremely worse. It’s just you’re paying more to get a bit better result. However, if you don’t have that much budget, there’s another option to go for that may lack a bit here and there.

Compatibility Table

Models5.7 Hemi Engine6.4 Hemi Engine
2003-Present Ram 1500/2500/3500YesNo
2015-2018 Dodge ChargerNoYes
2004-2009, 2011-Present Dodge DurangoYesNo
2015-2018 Dodge Challenger SRT 392 (R/T)NoYes
2005-2008 Dodge Magnum (R/T)YesNo
2011-2014 Dodge Challenger SRT 8NoYes
2006-Present Dodge Charger (R/T)YesNo
2014-Present Dodge Ram 2500 PickupNoYes
2009-Present Dodge Challenger (R/T)YesNo
2015, 2017-Present Dodge Challenger SRTNoYes
2005-Present Chrysler 300CYesNo
2016-2017 Ram 2500NoYes
2005-Present Jeep Grand CherokeeYesNo
2016-2017 Ram 3500NoYes
2006-2010 Jeep CommanderYesNo
2018-Present Dodge Ram 3500 PickupNoYes
2007-2009 Chrysler AspenYesNo

Wrap Up

So, we have reached the very end of this 6.4 hemi vs 5.7 hemi comparison. And thankfully, there’s also a clear winner to move ahead from this point.

The domination of 6.4 engine is pretty obvious now that we have explored each engine factor including horsepower, stroke, torque, and so on.

Hopefully such a detailed and in-depth weighting-up piece of writing will be able to guide you to the right purchase for your vehicle. See You in Some Other Automobile Chat Soon, Till Then Take Care.

About Steve

Hello! My name is Jeremy Bloomberg. I have been passionate about carpentry and DIY. Over the years, my passion slowly turned into expertise and wider knowledge about electronics. I’ve been involved in numerous projects, both professional and personal. I want to share all I have learned with you. Welcome!

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