
Getting a vehicle to start and move about takes a lot of energy conversions. And various conditions determine how efficiently an automobile will perform if it eventually starts. One of such conditions is the temperature level: Your car needs to operate under a not-too-hot or not-too-cold condition, else, the performance will be undermined or even worse, your engine could break down entirely.
That’s why a cooling system is necessary for every automobile. However, even the cooling system of a motor cannot work well without a thermostat! Because it is the thermostat that triggers the cooling system to either cool the engine or allow it to heat up to an optimal operational temperature.
With that said, you will agree that getting the best thermostat for 5.7 Hemi is very vital for your Chrysler Hemi Engine. But then, arriving at the best option might be a little tricky, given that you need some expert knowledge to know precisely which one to go for. Fortunately, that’s why my team and I are here to simplify things for you. Yet, before we go on to the product review, let’s get you up to speed with some buying guides to help you select the very best 5.7 Hemi thermostat.
Why Does Your 5.7 Hemi Engine Need A Thermostat?
Hemi engines, just like most automotive engines, are liquid-cooled — meaning that they need liquid coolants to regulate temperature levels.
The coolant basically flows from the lower tank to the engine block, around the cylinders and cylinder head, then towards the radiator. But then the thermostat ensures the coolant doesn’t just flow into the radiator until the temperature is above 180°F. In other words, the thermostat helps your engine to reach the ideal operating temperature as fast as possible.
By helping the car to warm up quickly, the thermostat reduces the rate of engine wear, deposits, and emissions.
On the other hand, when the coolant, and of course, the engine rises above 180°F and is becoming damagingly hot for the engine, the thermostat stabilizes the temperature of the engine by allowing the hot coolant to flow into the radiator where it dissipates heat and is readied for the next cooling cycle. Thus, the thermostat prevents overheating which when left unchecked can seize the engine. In some extreme cases, the piston can weld itself into the cylinder which will result in a damaged engine.
With that said, it’s important to install a thermostat in your 5.7 Hemi to warm up the engine and keep it within the optimal temperature.
Above all, getting the right thermostat is crucial because a faulty/underperforming thermostat is as good as nothing.
What Happens When You Run A 5.7 Hemi Vehicle Without A Thermostat
First off, your vehicle will NEVER reach the ideal operating temperature without a thermostat: That, of course, is very dangerous to the engine, because it will be more prone to wear, deposits, and emissions.
Secondly, your heater could blow cold air if your vehicle runs without a thermostat. This happens because driving a car without a thermostat tricks the engine into interpreting that it is cold outside. Hence, the engine adjusts the gas mixing valve and pushes more fuel to the engine.
That’s why driving a Hemi 5.7 vehicle without a thermostat will also result in poor fuel mileage and excessive fuel consumption.
Best Thermostat For 5.7 Hemi Reviews
Here, we’ve compiled a comprehensive review of 5 quality products to help you select the best thermostat for 5.7 Hemi. Let’s explore them one after the other.
1. ACDelco GM Original Equipment 131-151 Engine Coolant Thermostat

ACDelco is an original equipment thermostat produced typically for General Motors but also compatible with other similar engines. The parts appear in more than 2 million GM vehicles every year. Plus the thermostat can replace that of your factory-installed 5.7 Hemi (after some car tuning and fan adjustment) and offer similar durability and performance. The thermostat is especially recommended in 5.7 Hemi racing applications.
Key Features:
- Coolant Control: ACDelco thermostat ensures that the coolant is well controlled to regulate the temperature of the engine.
- Fast Warming: The 180 degree thermostat for Hemi features a valve that remains closed to warm up the engine to the ideal operating temperature as fast as possible.
- Precise Fitting: The thermostat fits precisely into General Motors’ original equipment. It is also compatible with Chryslers or other vehicles with 5.7 Hemi engines and provides similar functionality, reliability, and durability (after some adjustments, of course).
Pros
- A direct replacement for original equipment 180° thermostats
- Fits precisely in GM and other similar engines
- Warms up the engine fast enough
- Stabilizes the temperature of your engine at 180°F
- Offers a 2-year (unlimited mile) limited warranty.
Cons
- Prone to temperature fluctuations, especially if you fail to tune the 5.7 Hemi car and adjust the fan belt.
2. Mishimoto MMTS-JED-06L Racing Thermostat

Every high-performing Hemi engine needs a corresponding reliable cooling system to boost performance and service life. Luckily, Mishimoto is an ideal upgrade to your Dodge Charger/Challenger Hemi 2006-2019 original thermostat. Matter of fact, it can fit any of 5.7L, 6.1L, and 6.4L HEMI engines.
The overall quality of the product is evident from the manufacturer’s lifetime warranty which guarantees that your car spends more time on the road than in a mechanic’s workshop.
Key Features
- Lower Temperatures: The Mishimoto thermostat promotes cooling efficiency by significantly reducing the internal temperature of the engine as a result of upgraded and modified turbo applications.
- Full Thermostat Housing: The thermostat package comes with complete housing, giving you the option to replace both the thermostat and the housing if you so wish.
- Precise Stock Housing Fitting: In case the thermostat housing is not included in the package, Mishimoto designs its thermostat to precisely fit into any of the compatible original equipment housing.
- Rubber Gasket: The thermostat also features a rubber gasket that provides proper sealing.
- Higher And Lower Activation: Depending on your climate or the operational temperature requirements of your engine, the thermostat can offer lower activation by allowing the coolant to flow at 180° instead of the standard 203° to maintain a lower engine temperature. It can also offer a higher activation (203°) to ensure the temperature of your engine is optimal before releasing the coolant into the radiator. This goes a long way to preserve the service life of your engine.
Pros
- Ideal for original equipment replacement and upgrade.
- Fit precisely in all compatible 5.7 Hemi engines
- Enhances cooling efficiency
- Features thermostat housing
- Offers a lifetime warranty.
Cons
- Might not warm some engines fast enough.
- A relatively expensive option.
3. Stant 48792 OE Type Thermostat, Stainless Steel

If at all there’s any such thing as a perfect 5.7 Hemi thermostat, then Stant 48792 is a good example. As a brand, Stant prides itself on over 120 years of industry experience in the manufacture of original equipment parts and accessories. Through these years of experience, the brand has learned a lot and improved on each of its products (including the Stant 48792 thermostat, surely)
Manufactured with a combination of high-quality stainless and brass, the thermostat boasts longer service life than the average product in the market. What’s more interesting is that the package is available in various temperature ranges; hence, you are sure to secure the ideal specification for your car.
Key Features
- Cutting-Edge Technology Design: The Stant thermostat features a state-of-the-art design that bleeds air out of the system using bleed notches, check valves, and so on.
- High-Quality Stainless: Not every thermostat is carefully built for strength, toughness, and durability. But fortunately, Stant 48792 is exactly what you need if you don’t want to frequent a mechanic workshop for replacements or upgrades. The item features a stainless steel bridge with a channel design for durability and solidity. The stainless steel piston also guarantees longer life and tip-top performance.
- Stabilized Temperature: The product also comes with a stainless steel spring that encourages precise operating compression to allow your engine to reach the optimal temperature faster.
- A Ready-To-Install Assembly: The package is assembled in such a way that you need no extra work or modifications to install it after unboxing it.
Pros
- Guarantees extended durability
- Promotes smooth performance of the engine
- Ensures efficient air bleeding
- Improves temperature stability.
- Offers good value for a decent price.
Cons
- No reliable warranty
4. Gates 34053 OE Type Engine Coolant Thermostat

Gates Engine Coolant Thermostat is another reliable replacement for any original equipment 5.7 Hemi thermostat.
The Gates brand has engaged in lots of research and technology development over the past 100 years; thus, it’s a stalwart in the automobile parts industry. And you can rest assured that the thermostat is up to the mark in terms of controlling and stabilizing the cooling system of your 5.7 Hemi.
You need not worry about compatibility or performance because this thermostat is carefully manufactured to fit into any Dodge Ram 5.7 Hemi or similar engines. So, you will get the exact performance you anticipated.
Key Features
- Factory-Calibrated Spring: Gates OE thermostat features a factory-calibrated spring that ensures the smooth operation of the temperature valve. This smooth operation makes the valve open consistently, thereby stabilizing the engine’s internal temperatures.
- Calibrated Wax: The calibrated wax in the thermostat is highly sensitive to temperature changes and helps the valve to respond rapidly to extreme Cold or heat, thereby maintaining a not-too-hot or not-too-cold temperature. Of course, this condition enhances the service life of your engine.
- Vehicle-Specific Fit Type: The thermostat features a vehicle-specific fit type which means it is designed to precisely replace original thermostats for 5.7 Hemi or other related engines.
Pros
- Ideal replacement for original Equipment
- Consistent temperature regulation
- Fits precisely
- Real value for a little price.
Cons
- No gasket included
5. MotoRad 416-180 Thermostat with Seal

MotoRad is renowned for its full line of thermostats that are carefully produced and tested for quality, longevity, and performance. The aim is to ensure that your demands for an original equipment replacement are met or even surpassed.
The thermostat features a high-quality, dual-bridge stainless steel construction, and no doubt, once installed in your 5.7 Hemi, the difference will surely be clear.
Key Features
- Fail-Safe Technology: One unique feature of the MotoRad thermostat is the patented Fail-safe Technology that protects the engine when overheating happens. Before the Fail-Safe initiative, thermostats usually have little or no answer to unexplainable overheating. But with this new technology, whenever the engine overheats, the thermostat automatically gets stuck in the open position until the temperature is drastically reduced. This goes a long way to guarantee the safety of the engine.
- Enlarged Opening: The thermostat is made of stainless steel with an enlarged opening that allows a high flow of coolant. This increased flow helps to stabilize the internal temperature as quickly as possible.
- Bypass Valve: The high-flow thermostat also features a bypass valve that keeps the coolant in circulation before the thermostat fully opens up.
- Stainless Steel And Copper Construction: TheMotoRad thermostat is chiefly made of Stainless steel and copper which are highly durable and resistant to corrosion.
Pros
- Offers a reliable solution to overheating, thanks to the fail-safe technology
- Made of high-quality materials
- Easy to install and fits well
- Stabilizes the engine temperature at 180°
- Budget-Friendly
Cons
- Prone to high temperatures
Things To Consider When Buying A 5.7 Hemi Thermostat
Buying a new thermostat for a 5.7 Hemi engine can be tricky: First, because many available products can fit into other engines and not Hemi; secondly, because different qualities can either be standard or substandard.
Now, it’s noteworthy that a misfitting or substandard thermostat is as good as no thermostat at all; hence, it can cause more harm than good to your Hemi engine. That’s why you are always advised to go for the best.
Here are some factors to guarantee you are buying the right product:
1. The Material: It’s important to go for thermostats that are made of high-quality materials. This ensures durability and high performance.
We recommend you buy a product made of brass metal (for the body and valve).
Also, make sure that the artificial wax is reliable because it plays a vital role in opening or closing the valve to stabilize the engine temperature.
2. Temperature Range:You should also consider the temperature range of the thermostat you are about to buy and ensure it’s compatible with your Hemi engine.
Buying a thermostat that offers below or above the ideal temperature range can be catastrophic to your car engine.
We recommend that you buy a 203, 190, or 180 degree thermostat for Hemi since most 5.7 Hemi engines are compatible with thermostats with a temperature range of 180° to 203°.
3. Age Of The Car: Of course, the age of your car is ultimately determined by its production date. And the fact remains that some newer thermostats are not ideal for older car models and vice versa.
Hence, you should consider the age of your car when buying the best thermostat for 5.7 Hemi.
4.The Dealer: Ensure to always patronize a trusted dealer. Because, some vendors sell refurbished thermostats which are imitated as the new, original products! You don’t want to waste your hard-earned money on a substandard commodity.
5. Additional Features: To enjoy the best result from a 5.7 Hemi thermostat, we advise you to go for those products that offer some additional features.
For instance, some products feature bottom disks. Others feature bigger heat motors, or perhaps thicker springs and frames.
6. Warranty: It’s always a big bonus to buy products that offer some level of warranty. We always recommend such thermostats because they are generally more reliable.
Final Opinion
No matter how difficult it may seem to select the best thermostat for 5.7 Hemi, it will be a lot easier if you’ve followed this article from the beginning to this point.
Based on the buying guides we provided earlier, a reliable 180 degree thermostat for Hemi should be made of high-quality materials to ensure durability. It should maintain a stable temperature range to keep the engine safe. It should also offer additional features to boost performance. And above all, it should be provided by a reliable dealer.
Having said that, the Stant 48792 OE Type Thermostat is our top pick in this review because it offers all the aforementioned qualities at a very subsidized price.
However, if you want to spend a little more on a premium thermostat with a lifetime warranty, then we recommend Mishimoto MMTS-JED-06L Racing Thermostat.
FAQs About the Best Thermostat for 5.7 Hemi
1. What temperature should 5.7 Hemi run at?
The ideal temperature for a 5.7 Hemi engine is typically 203°F. However, a 180° thermostat fully opens just around that temperature.
2. What does a 180 degree thermostat do?
A 180 degree thermostat for Hemi will stabilize your engine temperature at 180°, thereby improving fuel mileage and lower emission. Besides, a lower engine temperature will go a long way to boost horsepower and torque.
3. Is a 180 thermostat worth it?
A 180° thermostat won’t add much to the everyday performance of your 5.7 Hemi engine unless a slight modification is done when it comes to car racing applications. However, a 180° thermostat is quite reliable if the engine is required to operate at a temperature range of 180°F to 195°F. Therefore, you should check your car manual to ascertain the temperature details of your engine.