The 5.7L HEMI V8 in your 2013 Ram 1500 fires 16 spark plugs per full engine cycle—not eight. That twin-plug design doubles your maintenance cost per swap and makes plug choice critical for idle smoothness, WOT response, and long-term electrode life. Pick the wrong heat range or electrode material and you’ll chase misfires on cylinders 4 and 8 for months.
I’m Amir — the founder and writer behind Four Wheel Ask. I’ve spent years analyzing aftermarket and OEM ignition components, cross-referencing heat ranges, gap specs, and thread reach against factory service manuals, owner feedback, and real-world wear patterns for the 2009–2018 Ram HEMI family.
This guide focuses on compatible options that match the factory 14mm thread, proper reach, and correct gap range for the 5.7L V8. If you’re looking for dependable, long-service replacements, these 2013 ram 1500 spark plugs deliver consistent performance without the headache of early fouling or pre-ignition.
How To Choose The Best 2013 Ram 1500 Spark Plugs
The 2013 Ram 1500 5.7L HEMI uses a twin-spark ignition—two plugs per cylinder—so you need 16 plugs for a full change. That multiplies the importance of choosing the correct heat range, electrode material, and gap tolerance from the start.
Electrode Material: Iridium or Copper?
Iridium plugs (fine-wire center electrode) resist wear longer, maintain a stable gap past 60,000 miles, and reduce misfire risk at high RPM. Copper plugs are cheaper per plug but wear faster in the HEMI’s twin-spark configuration, often requiring a gap check before 30,000 miles. For a 2013 5.7L that sees daily driving or towing, iridium is the smarter service interval choice.
Heat Range & Thread Reach
The factory heat range for the 5.7L HEMI is equivalent to an NGK heat rating of 5 or 6. Too-hot a plug (lower number) invites pre-ignition under load; too-cold (higher number) leads to carbon fouling on short trips. Thread reach must be 19mm (0.748 inch) with a 14mm thread diameter—never install a plug with a shorter or longer reach to match the piston clearance.
Gap Precision
The 2013 Ram 1500 5.7L spec gap is 0.043–0.046 inch. Do not assume pre-gapped plugs are correct for your engine, even from premium brands. Always verify with a wire-type gap tool. A gap outside this range causes partial-burn cycles, rough idle, or reduced fuel economy.
Quick Comparison
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| Model | Category | Best For | Key Spec | Amazon |
|---|---|---|---|---|
| NGK (4469) LFR5AIX-11 Iridium IX 8-Pack | Iridium | Long-service OE replacement | Iridium fine-wire, 14mm, OE heat range 5 | Amazon |
| Champion Copper Plus 16-Pack (5.7L HEMI) | Copper | Budget 16-plug replacement | Copper core, 14mm thread, 0.040 gap | Amazon |
| BDFHYK 6441 Iridium 8-Pack | Iridium | Multi-engine compatibility | Iridium center, OE #6441, 14mm | Amazon |
| BDFHYK Iridium 6-Pack (3.7L / 4.7L) | Iridium | Non-HEMI V6 / V8 engines | Iridium tip, #4504 PK20TT, 6 plugs | Amazon |
| Champion Copper Plus 8-Pack (5.2L / 5.9L) | Copper | 1997–2003 Magnum V8 engines | Copper core, compatible 5.2L/5.9L, 8-pack | Amazon |
In‑Depth Reviews
1. NGK (4469) LFR5AIX-11 Iridium IX Spark Plug (8 Pack)
NGK is the OE supplier for many Chrysler engines, and the LFR5AIX-11 maps directly to the heat range and thread geometry the 5.7L HEMI was designed around. The iridium fine-wire center electrode measures 0.6mm—small enough to concentrate the spark for reliable cold starts and consistent burn at high RPM. The trivalent metal plating on the shell resists corrosion, which matters when you’re pulling plugs at 60,000 miles on a truck that sees road salt.
Gap out of the box runs around 0.044 inch, right in the factory spec window. That saves you time if you’re swapping all 16 plugs in an afternoon, but NGK themselves recommend verifying gap with a wire tool—do not assume perfection. The 14mm thread and 19mm reach match the HEMI cylinder head without clearance issues on either the intake or exhaust side plugs.
Owners on Ram forums consistently report smoother idle after switching from copper or off-brand platinum sets, and the IX series holds its gap beyond 60,000 miles under normal driving. If you want a set that you install and forget for two service intervals, this is the easiest recommendation for the 5.7L HEMI.
What works
- OE-correct heat range and thread reach for the 5.7L HEMI
- Iridium fine-wire resists gap spread beyond 60,000 miles
- Corrosion-resistant plating reduces seizure risk
What doesn’t
- Sold as 8-pack—you need two sets for a full 5.7L HEMI change
- Pre-gap not guaranteed—must verify with tool
2. Champion Copper Plus 16-Pack (5.7L V8 2011-2024 HEMI)
The Champion Copper Plus 16-pack is built specifically for the HEMI twin-plug system—16 plugs in one box, no math, no second order. Each plug uses a copper core electrode with a nickel-alloy tip, which delivers good thermal conductivity and reliable spark for the factory 0.043–0.046 gap range. The 14mm thread and 19mm reach are correct for the 5.7L cylinder head, and the resistor construction suppresses RFI to keep your truck’s electronics clean.
Copper plugs wear faster than iridium, and Champion rates these for roughly 30,000 miles before gap erosion becomes a consideration. For a truck that sees moderate mileage or mixed light-duty use, that interval is workable.
The gap out of the box is factory-set at 0.040 inch, slightly tighter than the HEMI spec of 0.043–0.046. You should plan to re-gap each plug before installation. Owners report that after gapping correctly, the HEMI runs smoothly and the plugs serve their full 30K interval without misfire issues. If you do your own wrenching and don’t mind a quick gap adjustment, this is a solid budget option for a full 16-plug swap.
What works
- One box covers all 16 plugs for the 5.7L HEMI twin-plug system
- Copper core dissipates heat well for daily driving conditions
- RFI resistor keeps electronics interference low
What doesn’t
- Pre-gapped at 0.040—requires re-gapping to HEMI spec
- Wears faster than iridium; expect 30,000-mile change interval
3. BDFHYK 6441 Iridium Spark Plugs (8 Pack)
The BDFHYK 6441 iridium plug covers a broad range of Chrysler V6 and V8 engines including the 3.7L PowerTech, 4.7L, and the 5.7L HEMI used in the 2013 Ram 1500. The center electrode is iridium—fine enough to reduce required firing voltage and minimize misfire at high RPM—and the isostatic-pressed insulator provides consistent dielectric strength. TS16949 certification suggests a quality-controlled manufacturing line, not a bottom-shelf rebrand.
One detail to verify: the 6441 cross-ref includes the NGK ZFR6FIX-11 heat range, which corresponds to NGK’s heat rating of 6, one step colder than the factory-spec heat range 5 used in the 5.7L HEMI. That means the BDFHYK 6441 may be slightly more resistant to pre-ignition under high-load towing but could run foul-prone on short-trip, never-hot-enough cycles. For mixed driving, the difference is minor; for dedicated towing or performance tuning, the colder plug may actually benefit carbon buildup.
Customer reports on Ram forums show these gap out around 0.043–0.044 from the pack, which lands in the factory window. The 14mm thread and 19mm reach fit without clearance issues. If you need a multi-engine backup set for a fleet or you want to experiment with a marginally colder heat range for towing durability, the BDFHYK 6441 is a functional alternative at a lower entry price than NGK.
What works
- Iridium electrode for consistent spark and longer gap life
- Cross-compatible with Chrysler, Dodge, Jeep V6 and V8 engines
- TS16949 certified manufacturing
What doesn’t
- Heat range equivalent to NGK 6—one step colder than factory HEMI spec
- 8-pack only—need two packs for full 5.7L HEMI change
4. BDFHYK Set of 6 Iridium Spark Plug (3.7L / 4.7L V6 V8)
This 6-pack from BDFHYK targets the 3.7L V6 and 4.7L V8 engines found in the 2013 Ram 1500—not the 5.7L HEMI. If your truck has the 3.7L PowerTech or 4.7L Magnum/NGV, the #4504 / PK20TT cross-reference is correct. The iridium center electrode uses the same fine-wire approach as premium brands, and the isostatic ceramic insulator resists electrical leakage and thermal shock. OE-level manufacturing is claimed; the packaging includes housing and ground electrode pre-gapped from the factory.
One important distinction: the 3.7L uses six plugs total, so this set covers a complete change in one purchase. The 4.7L uses eight plugs—two per cylinder—so you would need two of these 6-packs plus two extra plugs to cover that engine. Before buying, confirm whether your 2013 Ram 1500 has the 3.7L or 4.7L, because the plug count and firing requirements differ significantly from the 5.7L.
Customer feedback indicates the pre-gap is close to the factory spec for the 3.7L and 4.7L engines, though some owners report re-gapping by 0.002 inch for optimal idle. The platinum core material listed in the specs suggests a dual precious-metal construction, which supports longer change intervals than standard copper. If you need a budget-friendly iridium option for the smaller displacement engines, this is a functional fit.
What works
- Correct for 3.7L PowerTech and 4.7L V8 applications
- Iridium center electrode for consistent firing and longer life
- 6-pack covers full change on 3.7L V6
What doesn’t
- Not compatible with 5.7L HEMI twin-plug system
- 4.7L V8 requires 8 plugs—set is short by 2
- Pre-gap may vary by 0.002–0.003 from factory spec
5. Champion Copper Plus 8-Pack (1997–2003 Ram 5.2L / 5.9L V8)
This Champion 8-pack fits the older 5.2L and 5.9L Magnum V8 engines from 1997–2003 Ram 1500 models, not the 2013 5.7L HEMI. If you have an earlier Ram that still uses the cast-iron Magnum block, the Champion Copper Plus is a direct replacement that matches the original 14mm thread and the wider electrode gap that those engines require (typically 0.035–0.040 inch). The copper core provides adequate thermal conductivity for the lower compression ratio of the Magnum series.
These plugs use a nickel-alloy ground electrode and a standard copper center electrode—no precious metals. Expect a service interval around 30,000 miles before the gap drifts wide enough to cause a noticeable misfire. For a 1997–2003 truck that sees light duty or occasional use, that interval is acceptable. The copper design also makes these plugs one of the more forgiving choices if your engine runs slightly rich from age—copper is more resistant to carbon fouling than fine-wire iridium in those conditions.
Note the fitment: the vendor listing targets 5.2L and 5.9L engines, not the later 5.7L HEMI. Verify your engine family before purchase. For any 2013 Ram 1500, this set is not the correct choice. Owners of older Magnum-powered Rams report easy starts and stable idle after installation, but the gap should be checked manually because the pre-set gap may shift during shipping.
What works
- Direct replacement for 1997-2003 5.2L and 5.9L Magnum engines
- Copper core resists carbon fouling on older, slightly rich engines
- Champion brand has decades of OE fitment history
What doesn’t
- Does not fit 2013 Ram 1500 5.7L HEMI—different heat range and gap spec
- Copper electrode wears faster than iridium; 30,000-mile typical life
- Pre-set gap may shift in transit; verify before installation
Hardware & Specs Guide
Thread Size & Reach
Every spark plug for the 2013 Ram 1500 5.7L HEMI uses a 14mm thread diameter with a 19mm reach (0.748 inch). The seat is a gasket-type taper—do not use plugs with a tapered seat design meant for Ford or GM applications. Cross-threading the aluminum HEMI head is expensive; always start plugs by hand and use a torque wrench to 15–20 ft-lb.
Heat Range & Material
The factory heat range for the 5.7L HEMI corresponds to NGK heat rating 5 (medium-hot) or NGK heat rating 6 (medium-cold) for towing or modified engines. Iridium plugs (NGK IX, BDFHYK) offer a 0.6mm fine-wire electrode that lowers required firing voltage. Copper plugs (Champion Copper Plus) use a standard nickel-alloy electrode with higher firing voltage demand and faster gap wear.
Twin-Plug System Requirements
The 5.7L HEMI fires two spark plugs per cylinder—one on the intake side, one on the exhaust side. Both must be the same heat range and gap specification. A common mistake is mixing old and new plugs or using different brands between banks, which leads to uneven combustion. Always replace all 16 plugs at the same service interval with identical part numbers.
Gap Specifications
The factory gap for the 2013 Ram 1500 5.7L HEMI is 0.043–0.046 inch (1.09–1.17 mm). Use a wire-type gap tool—not a ramp-style disc—to avoid bending the iridium tip. For the 3.7L V6, the spec is typically 0.040–0.043 inch; for the 4.7L V8, 0.043–0.046 inch. Always verify your engine’s specific spec from the under-hood emissions label.
FAQ
How many spark plugs does a 2013 Ram 1500 5.7L HEMI need?
What is the correct spark plug gap for a 2013 Ram 1500 5.7L?
Can I use copper spark plugs in a 2013 Ram 1500 HEMI?
What torque should I use when installing spark plugs on a 2013 Ram 1500?
Why does my 2013 Ram 1500 misfire after a spark plug change?
Final Thoughts: The Verdict
For most buyers, the 2013 ram 1500 spark plugs winner is the NGK (4469) LFR5AIX-11 Iridium IX 8-Pack because it matches factory heat range, thread reach, and gap spec for the 5.7L HEMI, and the iridium electrode supports a 60,000-mile service interval without gap drift. If you want a full 16-plug set for a single purchase, grab the Champion Copper Plus 16-Pack and re-gap each plug from 0.040 to 0.043–0.046 inch. And for a budget-minded iridium alternative that covers the 3.7L or 4.7L engines, nothing beats the BDFHYK 6-Pack Iridium Set.
Certification: BSc in Mechanical Engineering
Education: Mechanical engineer
Lives In: 539 W Commerce St, Dallas, TX 75208, USA
Md Amir is an auto mechanic student and writer with over half a decade of experience in the automotive field. He has worked with top automotive brands such as Lexus, Quantum, and also owns two automotive blogs autocarneed.com and taxiwiz.com.