2018 Ram ProMaster — Spark Plug Type & Gap
Your ultimate guide to spark plug replacement for the 2018 Ram ProMaster, including part numbers, gap, torque, and maintenance tips.
AI-generated reference. Always verify torque values, fluid capacities, intervals, and procedures against the manufacturer's service manual or OEM repair information before performing work. Repairius is not liable for damage from acting on this content without verification.
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Quick reference
| Engine | OEM Plug PN | Aftermarket (NGK/Denso/Motorcraft) | Gap (in/mm) | Torque (lb-ft / Nm) | Interval |
|---|---|---|---|---|---|
| 3.6L Pentastar V6 | Mopar SP148766AD (OE) | NGK LZKAR7D-8 (92211) / Denso ZC20HPR8 (5748) | 0.039-0.043 in / 1.0-1.1 mm | 18 lb-ft / 24 Nm | 100,000 miles |
Why the right plug matters
Choosing the correct spark plug for your 2018 Ram ProMaster is crucial for optimal engine performance, fuel efficiency, and longevity. Spark plugs are not a "one-size-fits-all" component; various factors like heat range, electrode material, and gap significantly impact how your engine runs.
Heat Range: The heat range of a spark plug refers to its ability to dissipate heat. A "cold" plug dissipates heat quickly and is suitable for high-performance or heavily loaded engines, preventing pre-ignition. A "hot" plug retains more heat and is better for engines that operate at lower temperatures, preventing fouling. Using a plug with an incorrect heat range can lead to issues like misfires, reduced power, and even engine damage.
Electrode Metal: The material of the spark plug electrode plays a vital role in its durability and performance:
- Iridium: This is the most advanced and expensive material, offering exceptional durability and a very fine electrode tip. This allows for a strong, consistent spark, improved fuel economy, and a longer lifespan, often exceeding 100,000 miles. Many modern vehicles, including your 2018 Ram ProMaster, come with iridium plugs from the factory.
- Platinum: Platinum plugs offer a good balance of performance and durability, lasting around 60,000-80,000 miles. They are more durable than copper but not as long-lasting as iridium.
- Copper: Copper plugs are the most affordable but have the shortest lifespan. Their larger electrode tip can lead to a less focused spark compared to iridium or platinum. They are generally not recommended for modern vehicles designed for longer-lasting plug materials.
How to gap a spark plug
Spark plug gapping is the process of adjusting the distance between the center and ground electrodes. An accurately gapped plug ensures a strong, consistent spark, which is essential for efficient combustion. For your 2018 Ram ProMaster 3.6L Pentastar V6, the recommended gap is 0.039-0.043 inches (1.0-1.1 mm).
Tools needed: A wire-type feeler gauge is the preferred tool for gapping. Avoid using a coin-style gapping tool, as it can damage the delicate iridium or platinum electrode tips.
Procedure:
- Carefully insert the correct size gauge wire between the electrodes. It should slide in with a slight drag.
- If the gap is too small, gently bend the ground electrode outwards using the gapping tool
More specs for the 2018 Ram ProMaster
Oil Capacity & Filter
Capacity, weight, filter PN, drain plug torque, change interval.
Fluid Type Specs
Engine oil, coolant, ATF, diff, brake, PS, DEF — with OEM spec numbers.
Coolant Capacity & Type
Total system capacity, OEM coolant spec, flush interval, bleed tips.
Transmission Fluid & Service
Trans model, fluid spec, capacity, filter PN, service interval.
Torque Specifications
Lug nuts, drain plug, caliper, axle nut, plug, key fasteners.
Brake Pad & Rotor Specs
Pad PNs, rotor size, min thickness, caliper torque.
Tire Size & Pressure
OEM size, cold psi, bolt pattern, wheel size, TPMS.
Battery Size & Group
Group size, CCA, AGM/flooded, dimensions, reset note.
A/C Refrigerant & Oil
R-134a or R-1234yf, charge oz, PAG oil spec.
Bulb Sizes (Headlight, Tail, Fog)
Headlight, fog, tail, turn, reverse, interior.
Factory Maintenance Schedule
Service intervals by mileage, severe-duty notes, known issues.
Towing Capacity & Payload
Max tow, payload, GVWR/GCWR, hitch class by trim.
Fuse Box Diagram & Amperage
Fuse box locations, layout, amps, and what each fuse controls.
Serpentine Belt Routing & Length
Belt routing, length, rib count, OEM + aftermarket PNs.
Wheel Alignment Specifications
Camber, caster, toe ranges (front & rear), adjustability notes.
Paint Color Codes
All factory colors with paint codes, sticker location, touch-up tips.
Wiper Blade Sizes
Driver/passenger/rear blade size, attachment, OEM + cross-refs.
Transmission & Axle Gear Ratios
Trans gear ratios, axle ratios, RPO codes, tow vs MPG impact.
Key Fob Programming
DIY programming steps, FCC ID, fob PN, battery, transponder.
Same spec — other model years
Maintenance & repair guides
2018 Ram ProMaster Maintenance Schedule →
Available maintenance guidance; confirm the manufacturer schedule.
Repair planning references →
Plan the scope of work; detailed procedures need configuration-matched evidence.
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