2023 Kenworth T680 Spark Plug Guide
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Quick reference
| Engine | OEM Plug PN | Aftermarket (NGK/Denso/Motorcraft) | Gap (in/mm) | Torque (lb-ft / Nm) | Interval |
|---|---|---|---|---|---|
| PACCAR MX-13 | N/A (Diesel) | N/A (Diesel) | N/A (Diesel) | N/A (Diesel) | N/A (Diesel) |
| Cummins X15 | N/A (Diesel) | N/A (Diesel) | N/A (Diesel) | N/A (Diesel) | N/A (Diesel) |
Why the right plug matters
The 2023 Kenworth T680 is exclusively offered with diesel engines, specifically the PACCAR MX-13 and the Cummins X15. Diesel engines operate on a compression ignition principle, meaning they don't use spark plugs to ignite the air-fuel mixture. Instead, they rely on the heat generated by compressing the air to ignite the fuel. Therefore, spark plug type, gap, heat range, and electrode materials like iridium, platinum, or copper are not applicable to these engines.
How to gap a spark plug
This section is not applicable to the 2023 Kenworth T680 as it is a diesel vehicle and does not use spark plugs.
Replacement procedure tips
This section is not applicable to the 2023 Kenworth T680 as it is a diesel vehicle and does not use spark plugs. Maintenance procedures for diesel engines focus on glow plugs (if equipped, which primarily aid in cold starting, not continuous ignition) and fuel system components, not spark plugs.
Known issues
Since the 2023 Kenworth T680 does not use spark plugs, common spark plug-related issues such as cracked porcelain, broken plug shells, or ionization-sensing coil problems (like those seen in some gasoline engines) are not relevant to this vehicle.
Need plugs replaced? Find a shop on Repairius.
More specs for the 2023 Kenworth T680
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
2023 Kenworth T680 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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Values can vary by engine, trim and build date; check your VIN-specific service information. Updated 2026-06-26.