2018 Peterbilt 579 Towing Capacity & Payload
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.
Working on this 2018 Peterbilt 579? Run just this one job through Repairius.
No big switch. Write the estimate, text it for approval, and get paid on your phone. Keep everything else the way it is.
14-day free trial · credit card required · cancel anytime
The 2018 Peterbilt 579 is not rated for conventional towing via a hitch receiver, nor does it have a specified payload capacity in the traditional sense. As a Class 8 commercial semi-truck, its primary function is to pull large semi-trailers using a fifth-wheel coupling.
Quick Answer
- Max Tow Capacity: Up to 80,000 lbs (GCWR for a typical tractor-trailer combination, depending on configuration and regulations)
- Max Payload: Not applicable in the conventional pickup/SUV sense; payload refers to the cargo weight within the attached trailer.
- GVWR (Gross Vehicle Weight Rating): Typically 33,000 lbs to 60,000 lbs+ (for the tractor itself, depending on axle configuration and ratings)
- GCWR (Gross Combination Weight Rating): Generally 80,000 lbs (standard U.S. limit for a tractor-trailer combination), but can be higher for specialized heavy-haul applications with proper permitting and equipment.
- Curb Weight: Varies significantly based on engine, transmission, cabin type, and accessories, but typically ranges from 16,000 lbs to 22,000 lbs for a tractor. Lightweight configurations can be less, heavy-spec more.
- Hitch Class: Not applicable; uses a fixed or sliding fifth-wheel coupling for semi-trailers.
Tow Ratings by Engine & Trim
For a Class 8 truck like the Peterbilt 579, "towing capacity" is less about a specific hitch rating and more about the Gross Combination Weight Rating (GCWR) and the truck
More specs for the 2018 Peterbilt 579
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.
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.
Spark Plug Type & Gap
Plug PN, gap, torque, interval by engine.
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 Peterbilt 579 Maintenance Schedule →
Available maintenance guidance; confirm the manufacturer schedule.
Repair planning references →
Plan the scope of work; detailed procedures need configuration-matched evidence.
Browse by make
Running an auto or diesel repair shop?
Compare Repairius to the shop software you're paying for
$99.99/month (first location included), unlimited users, 14-day free trial.