Overview

Overview
This 2026 Peterbilt Model 548 Medium Duty is being sold as a new, bare chassis — no body is currently installed. It's spec'd for other-commodity hauling in city delivery service, on a 274" wheelbase with a 54,600 lb GVWR / 54,600 lb GCW and an estimated as-configured weight of 20,013 lbs (engineering estimate; actual shipping weight may vary with unpublished options).

Engine & Drivetrain
Powered by a PACCAR PX-9 rated 350 HP @ 2,000 RPM (governed @ 2,200 RPM) with 1,050 lb-ft of torque @ 1,200 RPM, built to 2024-emissions Productivity specification, EPA emission compliant with EPA engine idling compliance. Paired with an Allison 3000 RDS-P Gen 6 Rugged Duty Series automatic transmission, configured as a 6-speed with close-ratio gears, Allison World Trans primary shift schedule 1, HS/RDS package 223, TC-421 torque converter, neutral-at-stop, and a dash-mounted push-button shifter. A 1710 HD driveline with 2 midship bearings runs to the rear axle. PTO provisions include a Chelsea F/O mount, LH-mounted trans PTO provisions, a dash-mounted single-acting EOH PTO control (electric over hydraulic), park brake interlock for the transmission-mounted PTO, and a remote PTO/throttle 12-pin engine-bay remote control provision. Additional engine equipment includes a VGT exhaust brake, high-efficiency cooling system, engine-mounted air cleaner, PACCAR fuel/water separator with 12V heated fuel filter, engine protection shutdown with label, a single RH-side DPF/SCR exhaust module under the cab with a curved-tip, 36" chrome standpipe with clear coat, a 160-amp brushed alternator, a 110–120V immersion-type block heater, 2 PACCAR premium 12V starting batteries (2,000 CCA), a low-voltage disconnect system, a Horton on/off fan clutch, and an 18.7 CFM air compressor. Engine parameters are factory-configured for the application, including a 65 MPH typical operating speed, standard and hard maximum speed limits, cruise control speed/auto-resume settings, idle shutdown with ambient-temperature override, and gear-down protection.

Chassis & Axles
Front axle is a Meritor MFS+14F rated 14,600 lbs with a 3.5" drop, wide-track configuration, taper leaf springs, and shocks. Steering is a frame-mounted Sheppard SD110 power steering unit. Front brakes are Bendix air cam drum brakes, 16.5x5, with dust shields and gusseted cam brackets; hubs are PHP10 iron preset+. Rear axle is a Meritor MT40-14X rated 40,000 lbs with heavy-wall drive axle housings, gusseted cam brackets, camshaft reinforcement, PHP10 iron preset+ hubs, an SBM valve, pneumatic park brake, synthetic axle lubricant, and Bendix air cam drum brakes, 16.5x7. ABS is a 4S4M system, rear axle ratio is 5.29 with diff lock on the tandem (speed interlock). GVWR is 54,600 lbs with a GAWR of 14,600 lbs front and 20,000 lbs on each intermediate axle position; front axle load is 14,600 lbs and rear axle load is 40,000 lbs. The frame consists of 10-3/4" steel rails (403"–444" length) at 3/8" thickness with a full steel inner liner, an HD 5-piece crossmember (BOC, IPO standard for Class 5/6/7), and aluminum frame rail crossmembers (excluding suspension). Wheelbase measures 274", cab-to-axle is 206.50", frame-to-BOC is 67.50", and cab-to-end-of-frame is 313.30". Maximum grade rating is 6%. Frame is configured with a custom wheelbase/overhang, frame rake exceeding standard recommendations, and a square end-of-frame without a crossmember (for body-builder-installed crossmember); rear mudflaps and hangers are omitted. Fuel capacity totals 100 gallons via dual 50-gallon D-shaped aluminum tanks (RH and LH, behind cab), with a small 14-gallon (2.1M) DEF tank mounted LH BOC at a 1:1 DEF-to-fuel ratio; chassis is confirmed centrally fueled. Chassis also includes a medium-duty battery box with non-slip step (LH under-cab), rubber battery pad, aluminum battery box cover, an aluminum non-slip aftertreatment cab entry step (RH under-cab), and a tapered chrome steel bumper with 2 tow points.

Suspension
Rear suspension is a Peterbilt Air Trac rated 46,000 lbs with a 54" spread. Cab air suspension is also equipped.

Cab & Interior
The cab is a Peterbilt Aero 107" BBC with an SMC hood featuring a molded charcoal crown and aluminum cab construction, a bright-finish hood crown (IPO molded gray), and a thermal insulation package. Interior is finished in ProBilt charcoal gray with a curved roof. Seating includes a Sears driver seat (air ride, high-back, vinyl) and Sears passenger seat (non-air ride, high-back, vinyl), with driver and passenger armrests. Steering column is adjustable (tilt/telescope) with a Peterbilt-logo steering wheel. Glass includes a one-piece curved windshield and a fixed one-piece glass rear cab window (day cab configuration). Power door locks and power window lifts are standard, along with a combination fresh-air heater/air conditioner and a floor-mounted cup holder. Exterior mirrors include motorized, heated Peterbilt aero mirrors with integrated convex lenses in a bright-finish housing, a look-down mirror over the passenger door with black housing, and bright-finish round hood mirrors with SST tube arms. Audio includes a ConcertClass AM/FM/WB radio with 3.5mm aux input, a standard 2-speaker package, Bluetooth phone/audio, and a USB port. Additional cab equipment includes global telematics hardware, electric windshield wipers with intermittent feature, an additional dash switch with wiring behind the dash, auto-reset circuit protection, a triangle reflector kit (ship loose), a driver-seat-mounted fire extinguisher, and a 107 dB backup alarm. The digital cluster includes a 7" display showing transmission oil temperature and engine hourmeter, a dual-scale speedometer (MPH over KPH), and an air restriction indicator. Lighting includes composite fender-mounted headlights with integral DRL/park/turn/side marker, 5 aero LED marker lights, self-canceling turn signals, bumper-mounted daytime running lights (driven by chassis height), incandescent square stop/turn/tail/backup lights, and a switched flood/load light with a 10' coil cord for cab/sleeper mounting.

Body & Equipment
This unit is sold as a bare chassis — no body is currently installed. The chassis is engineered to accommodate a flatbed-style body up to 312" long x 102" high with a 1,000 lb maximum laden weight rating, and the frame is prepped accordingly with a square end-of-frame for a body-builder-installed crossmember. Body-mounting provisions include a 7-way electric harness socket mounted at end-of-frame, body connections 5' back-of-cab, and a Trucklite junction box at the LH end-of-frame. Exterior finish is a two-stage Axalta paint in white (cab, hood top, fenders, cab roof) with a black frame.

Tires & Wheels
Front tires are CN 16-ply 12R22.5 HSC3 with TPMS sensors, mounted on Alcoa 880677 22.5x8.25 high-polish aluminum wheels. Rear tires are CN 14-ply 11R22.5 HDR2+ (qty. 8), mounted on Alcoa 880677 22.5x8.25 high-polish aluminum wheels (qty. 8).

Warranty & Protection
Backed by Peterbilt Class 7 standard coverage of 1 year/unlimited miles, PACCAR PX-9 standard coverage of 2 years/250,000 miles (402,336 km)/6,250 hours, and a base emissions warranty of 5 years/100,000 miles. Also includes a 5-year SmartLinQ remote diagnostics subscription (PACCAR PX engines).