Think of spark plugs like the most basic but essential component of a gas engine. You get a good one and everything else works well. But if you get a bad spark plug, not only do you suffer a power loss, it will reduce your efficiency too. Plus, bad effects will happen in the long run. If it’s the time to replace your truck’s spark plugs, or if you’re looking at swapping the current ones for a set of high-performance models, our latest guide will help you find the best spark plugs for 5.7 Hemi. It’s a fairly popular V8 engine (and a much-loved one as well), so it’s safe to say that there are quite a few spark plugs to choose from.
Alternatively, if you’re looking for spark plugs for other trucks, we might have what you’re looking for.
- 5.7 Hemi Spark Plugs Reviews:
- REVIEWS YOU CAN TRUST
- 1. Top Quality: NGK Iridium Spark Plugs (8 Pack) – the Best Spark Plugs for 5.7 Hemi
- 2. Intermediate solution: ACDelco 20 Professional RAPIDFIRE Spark Plug
- 3. Factory replacement: OEM Mopar Spark Plugs – Set of 16
- 4. Platinum appeal: Autolite Platinum Spark Plug
- 5. Good performance and long service life: Bosch Double Iridium OE Replacement Spark Plug
- What are the best spark plugs for 5.7 Hemi?
5.7 Hemi Spark Plugs Reviews:
REVIEWS YOU CAN TRUST
We strive to always give you genuine, accurate information. To do this, all of mechanicguides.com reviews are based on market research, expert input, and practical experience. This knowledge comes from a team of automotive journalists and an independent mechanic, Steve “Whip” Whipple who has 11 years of experience in the auto industry. For more information, see here.
1. Top Quality: NGK Iridium Spark Plugs (8 Pack) – the Best Spark Plugs for 5.7 Hemi
This NGK spark plug is made of Iridium, the choice for high-performance engines. Plus, it requires less effort from the electrical system and is bound to last longer as well. There’s no modification required to use these since they’re OE replacements.
Fine-wire center electrode
The spark plug comes with high-grade alumina silicate ceramic and fine wire center electrodes. The iridium tip is what differentiates it from the lesser models. While performance gains are likely to be marginal only, it offers improved acceleration, better fuel efficiency, and longer life. The trivalent metal plating offers anti-corrosion and anti-seizing properties. The spark plug has a wrench diameter of ⅝ inches, a spark plug reach of 1.043 in, a thread size of 14 mm, and a Copper electrode core.
Why do we like it?
To complement a high-performance engine, the NGK Iridium Spark Plug is a good product. That’s because, with an Iridium-tipped electrode, it requires less effort for combustion, therefore making the process more efficient and less taxing on the electrical system of the vehicle. The Iridium spark plugs are bound to last longer than the standard ones — and the cost difference isn’t huge, either. There’s no warranty information available on the listing, but make it a point to ask the seller before making the purchase.
Because spark plugs are made for many different engines, you should also ask them about compatibility, keeping in mind the basic specs for fitment like thread size, for example. To be sure of your purchase, it’s always a good idea to ask. Generally, if you’ve got a 5.7 Hemi engined vehicle from Chrysler, Dodge, Jeep, or Ram, the plug will ideally fit. Also, check if the set you’re ordering is pre-gapped.
- Iridium — so the best you can buy
- Pack of eight — perfect for a V8 engine
- Limited info available (Amazon)
2. Intermediate solution: ACDelco 20 Professional RAPIDFIRE Spark Plug
- Solid state suppressor, with two-piece glass and brass seal, can help reduce radio frequency interference, regulates spark energy for long electrode life, and helps protect against high combustion pressures
- Pure copper core provides great heat transfer and helps maximize plug durability
- Platinum on center electrode enables superior spark characteristics and can reduce voltage requirements of the ignition system
- Ribless insulator helps optimize plug to boot seal
This is a platinum spark plug, so in terms of effectiveness, it sits between the stock units and the more performance-focused iridium ones. While you miss out on some of the benefits of the iridium models, you get longer life and better output than conventional plugs. In addition to that, the price difference isn’t too wide to take that leap. In this case, it’s an individual product, so to replace the old plugs on your 5.7 Hemi, you’ll need to order accordingly. As a general rule, if your truck uses two plugs per cylinder, then you’ll need to order 16 of these for a V8 engine. That’s exactly the case with the 5.7 Hemi.
The plug comes with high-quality suppressors that prevent misfiring and improve the long life of the electrode. Its copper-core ensures that there’s consistent heat transfer and the plug’s durability isn’t compromised, either. The central electrode gets platinum, which offers superior (to stock) spark characteristics. It’s also got a ribless insulator.
Why do we like it?
Like the Iridium product, this ACDelco 20 Professional Rapidfire Spark Plug also puts less burden on the electric system, although Iridium’s load is even less. Choosing a platinum spark plug over a conventional one is easy because the former is likely to function better for longer. The cost difference between it and the conventional units isn’t much, so if you’re looking at upgrading, this is a great intermediate solution.
The spark plug is backed by a 3-year/unlimited-mileage warranty. But it’s always a good idea to check with the seller if there are any exceptions. In terms of compatibility, there are a lot of vehicles that accept this. The relevant ones are from Chrysler, Dodge, Jeep, and RAM. Check with the seller if it’d fit your Hemi-engined vehicle and what model years are compatible. For instance, in the case of the Chrysler 300C, for the 5.7-liter V8 model, as long as the car was made between 2009 and 2018, it’s compatible.
3. Factory replacement: OEM Mopar Spark Plugs – Set of 16
The factory set of 16 spark plugs for the 5.7 Hemi engined products is a one-stop solution for your spark plugs needs. You buy one set and you’re done — no need to worry about ordering two of 8-pack or 16 of the individual units. Since it’s a factory item, you don’t have to worry much about compatibility and warranty (details on both below) or fit, for that matter.
Works just fine
It’s a factory-spec Nickel spark plug, so don’t expect any performance gains compared to other aftermarket spark plugs. The same can be said about a longer life; it’ll be the same as stock. But having said that, it’s by far the safest choice, because your car/truck most likely already comes fitted with this. So if you haven’t had an issue with the original set, maybe just stick with what you know?
Why do we like it?
These OEM replacement plugs from Mopar are an easy choice as long as you’re okay with buying what your truck came with as new. It’s thoughtful of Mopar to have a pack of sixteen on sale. That makes it easier to buy and keep a track of warranty and other details — something tricky to do with individual packs of spark plugs.
Check with the seller about a few things: warranty (the listing sadly doesn’t have info on that), compatibility (list of vehicles is mentioned below, but if you want to ask finer compatibility details, send them a message), and if it comes pre-gapped. The latter is verified by some users but it can be seller-dependent. Regarding the list of vehicles, Mopar mentions that the plug can be used on Dodge Challenger (2009 – 2013), Dodge Charger (2009 – 2017), Dodge Ram 2500/Ram 2500 (2010 – 2013), Ram 1500 (2012, 2013), Ram 3500 (2011 – 2013), Dodge Durango (2011 – 2014), Chrysler 300 (2009 – 2013), Jeep Commander (2009 – 2010), and Jeep Grand Cherokee (2009 – 2013).
4. Platinum appeal: Autolite Platinum Spark Plug
- Full platinum tip ensures virtually no gap erosion for long plug life
- Yttrium enhanced, high nickel alloy side electrode maintains precise gap to increase plug life
- Necked-down center electrode fires quicker and cleaner, with less voltage for easier starts, quicker acceleration, and improved fuel economy
- Platinum alloy pad on ground electrode provides extended durability and service life and platinum-to-platinum firing
- Nickel-plated steel shell for long-life corrosion resistance
Available as individual units or a set of four (like the one featured here), the Autolite Platinum Spark Plug is a cost-effective solution to replacing your 5.7 Hemi’s spark plugs. Since it’s got a platinum tip, you’re ideally looking at a longer life than a standard plug, less voltage required for operation, and improved performance.
The plug has a 14 mm thread, a hex size of ⅝ inches, and comes pre-gapped at 0.44 inches. The center wire platinum firing tip is complemented by a yttrium-enhanced, high-nickel alloy side electrode. There’s a platinum alloy pad on the ground electrode as well. The shell is made of nickel-plated steel, which adds corrosion resistance to the plug. It’s guaranteed for 4 years.
Why do we like it?
It’s a platinum plug, so it’s bound to be slightly better than the conventional ones. But the Autolite Platinum is priced so well, that it’ll be hard to ignore. It can be used in vehicles like the Chrysler 300 (2009 – 2019), Chrysler Aspen (2009), Dodge Challenger (2009 – 2019), Dodge Charger (2009 – 2019), Dodge Durango (2009, 2011 – 2018), Dodge Ram 1500 / Ram 1500 (2009 – 2010; 2011 – 2019), Dodge Ram 2500 / Ram 2500 (2009 – 2010; 2011 – 2018), Dodge Ram 3500 / Ram 3500 (2009; 2011 – 2018).
5. Good performance and long service life: Bosch Double Iridium OE Replacement Spark Plug
- Double Iridium firing pin and ground electrode inlay provide 4X longer service life compared to standard copper plugs
- 0.6mm fine wire firing pin provides superior ignitability and performance
- 360 Degree continuous laser weld fuses corrosion resistant iridium firing pin to base for increased durability
- 7 year performance satisfaction
- Original equipment, pre-gapped replacement delivering optimum fit, form and function
The Bosch Double Iridium plug comes with a promise of long life and improved performance. It has an iridium firing pin and an iridium ground electrode. The factory fit and specifications ensure you don’t have to worry about fit or compatibility (more on that below). Bosch also claims that the plug comes with a service life that’s four times as long as standard copper plugs.
7-year satisfaction guarantee
Bosch has a wide range of spark plugs available in the listing, with options of various platinum and iridium ones. You also get a choice of getting individual units, a pack of 10, or a pack of 4 (like this one). You can let your budget decide how you want to get the 16 that you need. The plug is made more durable with laser welds whereas its 0.6 mm fine wire firing pin offers better performance and ignitability. The plug is backed by a 7-year satisfaction guarantee.
Why do we like it?
Bosch makes a big claim with its Iridium plug — a service life that’s four times as long as conventional plugs. That shows the confidence the brand has in it. And since you don’t want to change spark plugs every couple of months, it might make sense to spend on something that lasts longer.
The Bosch Double Iridium spark plug is compatible with a variety of 5.7 Hemi engined vehicles including Chrysler Aspen (2009), Chrysler 300 (2009 – 2017), Dodge Challenger (2009 – 2018), Dodge Charger (2009 – 2018), Dodge Durango (2011 – 2018), Dodge Ram 1500/Ram 1500 (2009 – 2018), Dodge Ram 2500/Ram 2500 (2009 – 2018), Dodge Ram 3500/Ram 3500 (2009, 2011 – 2018), Jeep Commander (2009 – 2010), Jeep Grand Cherokee (2009 – 2018). Check with the seller about warranty, finer compatibility details, whether the plugs are pre-gapped, etc.
What are the best spark plugs for 5.7 Hemi?
The best bit about spark plugs is that there isn’t a big cost difference between conventional, Platinum, and the range-topping Iridium ones. So if you can slightly increase your budget you can put in the best plugs on the market. Before going further, let’s be clear that it’s not about the overall performance difference in stock setups. Because in everyday driving scenarios, there isn’t much difference to be experienced, but where the difference lies is largely in longevity.
An Iridium plug is bound to last you longer than a platinum one, while a platinum one will ideally work longer than a conventional one. How frequently you need to change the spark plugs might be something to consider since some trucks don’t make that an easy thing to do. You probably don’t want to get under the hood too often if that’s the case for your truck.
If you’re looking at the best plugs and are okay in spending slightly more on the Iridium plugs, then we’d suggest looking at both NGK Iridium plugs and the Bosch ones. Both will fit the 5.7 Hemi — have a wide variety (in terms of compatible models) — and will last fairly long. There is bound to be some performance increase in both, although don’t expect huge improvements with the stock setup.
There are a few Platinum choices as well. For instance, both Autolite and ACDelco models are Platinum plugs. The Autolite one comes pre-gapped, promises to last long, and has a corrosion-resistant shell. The ACDelco one comes with suppressors that ensure misfires don’t occur. It’s got a ribless insulator in addition to the usual features on spark plugs. The Autolite model is backed by a four-year guarantee whereas the ACDelco one has a 3-year/unlimited-mileage warranty backing it. But, in the end, if you don’t want to stray too far from the factory setup, then you can also look at what’s the safest solution here: a pack of 16 spark plugs by Mopar.