Kenworth T680

The T680 is Kenworth’s on-highway conventional tractor, which Kenworth calls a Class 8 truck; the US weight classes are explained in GVWR, GCWR and GAWR. Kenworth, a PACCAR company, introduced it in March 2012 and has built it since May 2012. The current version was launched on 11 February 2021 as the T680 Next Generation; Kenworth’s present T680 page lists its “Next Gen” lighting and “Next Gen SmartWheel” under the plain name T680. This page is built from Kenworth’s US T680 product page as captured by the Internet Archive on 3 May 2026, and from Kenworth’s T680 brochure (T680/24) and heavy-duty Body Builder Manual dated September 2024, also read in Internet Archive captures; from Kenworth Mexicana’s T680 page and its T680 Next Gen spec sheet dated 30 August 2024, read on 7 October 2026; from PACCAR Powertrain’s 2025 spec sheets for the MX-13 and MX-11 engines, the TX-12 and TX-18 gearboxes and the DX-40 axle; and from Kenworth’s press releases of 2012 to 2025, read in Internet Archive captures made between January and April 2026, and Kenworth Mexicana’s of 2017 to 2024.

Overview and generations

Kenworth introduced the T680 at the 2012 Mid-America Trucking Show in Louisville; its release of 21 March 2012 quotes Kenworth’s chief engineer calling it “Kenworth’s most aerodynamic truck…ever” and offers it with a new 76-inch sleeper or as a day cab, with the 12.9-litre PACCAR MX engine as standard and the Cummins ISX15 as an option. On 31 May 2012 Kenworth announced that production had begun at its assembly plant in Chillicothe, Ohio. The same release set the T680 beside the T660 and the T700, three aerodynamic models with cab widths of 1.9, 2.1 and 2.3 metres respectively. Kenworth says the T680 “carries on the legacy of the Kenworth T600”, which it calls “the industry’s first truly aerodynamic model introduced in 1985”. Kenworth Mexicana’s history page lists the T600 in Mexico from 1991, the T2000 from 1998, the T660 from 2005 as “una actualización del aerodinámico T600” (an update of the aerodynamic T600), and the launch of the T680 and T880 with the PACCAR MX-13 engine in 2013.

Kenworth launched the T680 Next Generation with four releases dated 11 February 2021. They describe a hood and grille eight inches narrower than before, new LED headlamps, a patented fender vent that lets air out from under the hood, optional side extenders reaching 28 inches in total length, an A-pillar turning vane, tandem drive-axle fairings, and a 15-inch digital instrument display. Kenworth’s fuel claim at that launch was up to 6 percent on a T680 Next Gen with a 76-inch sleeper and an EPA 2021 MX-13 engine over a comparably specified T680 with an EPA 2017 MX-13; its current page claims up to 7 percent over a similarly specified “T680 classic”. Kenworth’s release of 21 May 2021 reports the delivery of the first production T680 Next Generation, to Werner Enterprises at the Chillicothe plant, and lists day cab, 40-inch, 52-inch and 76-inch sleeper versions with the PACCAR MX-13, TX-12 and DX-40 as standard. On 5 August 2021 Kenworth announced that the T680 Next Generation had received the US Environmental Protection Agency’s SmartWay designation. Kenworth Mexicana announced the T680 Next Gen for Mexico on 1 April 2022, with the Cummins X15 or with the PACCAR MX-13 in a powertrain with the PACCAR 12-speed gearbox and 40,000 lb PACCAR rear axles; its history page dates the launch to 2022.

Kenworth calls the earlier version the “T680 Classic”. Its T680 Classic page, captured on 9 April 2025, lists the EPA 2021 MX-13, the TX-12 and the DX-40 tandem as standard, and Kenworth Mexicana’s release of 30 May 2022 reports a fleet delivery of 15 “T680 clásico” tractors of model year 2023 with Cummins X15 Euro V engines, Eaton 18-speed gearboxes, Dana axles and 52-inch sleepers. The model menu of Kenworth’s site captured on 3 May 2026 lists no T680 Classic. For its centenary in 2023 Kenworth introduced a T680 Signature Edition with 76-inch mid-roof or high-roof sleepers, its production limited to that year, and Kenworth Mexicana a T680 Edición Conmemorativa Kenworth 100 with the 76-inch high-roof sleeper, whose production was to start in May 2023 at its plant in Mexicali, Baja California.

Cab

The T680 has a 2.1-metre cab of stamped aluminium. Kenworth’s 2012 release describes aluminium panels joined with self-penetrating Henrob fasteners, a cab 83 inches wide with 23 inches between the seats, and a three-piece hood of sheet moulding compound (SMC) that opens with 35 lb of force; Kenworth Mexicana’s 2024 sheet lists the stamped aluminium cab, a curved windshield, the three-piece SMC hood, Daylite doors and air suspension for cab and sleeper. Kenworth’s Body Builder Manual of September 2024 draws the T680 with two hoods, a standard hood and a shorter “MX Optimized” hood, and with a day cab and 40-inch, 52-inch and 76-inch sleepers:

Every T680 drawing places the front axle 50.5 inches behind the bumper; the front axle sits 74.1 inches ahead of the back of the cab with the standard hood and 68.2 inches with the MX Optimized hood. The manual gives heights from the bottom of the frame rail and says that the ride height of the suspension has to be added to them for the overall height. Kenworth Mexicana’s 2024 sheet draws a 76-inch high-roof tractor with the dimensions 208.5, 127.5, 50.5 and 159 inches and says the dimensions of its drawings are approximate.

The 2024 brochure lists the sleepers as the 76-inch High-Roof, the 76-inch Mid-Roof and the 52-inch Flat Top. In December 2017 Kenworth Mexicana announced a 76-inch mid-roof sleeper for the T680 and T880, available to order from 1 January 2018, describing it as 22 inches lower than the 76-inch high-roof sleeper, about 100 lb lighter depending on the configuration, and 88 inches wide; Kenworth’s 2012 release gave the 76-inch sleeper a width of 96 inches and 60 cubic feet of storage. How sleeper and day cabs differ in general is covered in truck cabs explained.

Inside, the brochure lists two trim levels, Vantage and Diamond VIT, in Slate Gray or Tan; the 15-inch digital display, which it says all of Kenworth’s heavy-duty 2.1-metre cabs now feature; and the SmartWheel, updated to control the display. The US page calls it the Next Gen SmartWheel and lists cruise-control, headway and phone controls on it. Kenworth’s display release of February 2021 says the screen can show as many as 38 gauge functions, against approximately 23 on the trucks of the time, with nearly 50 layout possibilities and more than 4,500 gauge-view combinations. Options include the Driver’s Studio package with a 180-degree swivel passenger seat and a swivel table, and a cargo shelf of over 8.5 square feet and 5.5 inches deep in place of the upper bunk; the brochure also shows a drawer-style refrigerator/freezer, an 1800-watt inverter with up to four 120-volt outlets, a premium audio package with a 320-watt amplifier, a 10-inch subwoofer and 8 speakers, and a swivel TV mount for screens up to 28 inches. Outside, the brochure lists front air dams, A-pillar turning vanes, 19-inch side extenders, chassis fairing extenders and exhaust cut-out covers as standard, with 28-inch extenders, wheel covers and tandem fairings as options. The US page offers LED or halogen headlamps, and the brochure lists the LED headlamps, with built-in heaters, as an option. The US page describes a 17.3-inch LED side turn indicator mounted to the trailing edge of the hood; the brochure gives the side turn indicators as 17 inches long.

Engines

Kenworth’s US page lists the PACCAR MX-13 as the standard engine and the PACCAR MX-11 as the option.

PACCAR’s sheet describes the MX-13 as an inline six-cylinder engine of 12.9 litres with a 130 mm bore and 162 mm stroke, a dry weight of 2,500 lb, an oil system capacity of 42 US quarts, a governed speed of 2,100 rpm, EPA 2024 certification and a maximum operating weight of 140,000 lb, with oil-change intervals of up to 75,000 miles; PACCAR claims up to 450 lb less weight than 15-litre engines. The two documents give the 485 hp rating’s peak torque at different engine speeds. The MX-11 is a 10.8-litre inline six with a 123 mm bore and 152 mm stroke, a dry weight of 2,200 lb and a governed speed of 2,100 rpm, rated at 355 hp with 1,250 lb-ft, 375 hp with 1,350, 400 hp with 1,450, 415 hp with 1,550, 430 hp with 1,650 (or 1,450/1,650 as a multi-torque rating) and 445 hp with 1,700 lb-ft, all at 900 rpm, for a maximum operating weight of 110,000 lb. The brochure says the Driver Performance Assistant, which scores driving technique, is standard on every Kenworth with an MX-13, and lists Predictive Cruise Control and Predictive Neutral Coast. No Kenworth or PACCAR document opened gives kilowatt or newton-metre figures for these engines; how the units relate is set out in reading truck power figures.

On 11 June 2024 Kenworth introduced a version of the MX-13 that complies with the California Air Resources Board’s 2024 requirements, for the T680, T880 and W990, with production to begin in the fourth quarter of 2024. Kenworth names a twin-canister selective catalytic reduction aftertreatment and two ratings, 455 hp with 1,650 lb-ft and 510 hp with 1,850 lb-ft. PACCAR’s CARB MX-13 sheet adds a flywheel-driven 48-volt generator that powers an electric heater in the aftertreatment, a dry weight of 3,100 lb, an aftertreatment weight of 412 lb and a governed speed of 2,200 rpm.

For natural gas, Kenworth announced on 15 May 2024 that T680 and T880 trucks with the Cummins X15N would enter production in the third quarter of 2024. The X15N runs on compressed, renewable or liquefied natural gas and produces 400 to 500 hp with up to 1,850 lb-ft, with Eaton Cummins Endurant or Allison transmissions; back-of-cab fuel systems deliver up to 175 diesel gallon equivalents, and the same release says that earlier in 2024 Kenworth had delivered a T680 with the X15N to UPS. Kenworth’s release of 29 July 2021 made the 12-litre Cummins Westport ISX12N natural gas engine available in the T680 Next Gen, at up to 400 hp and 1,450 lb-ft.

Mexico. Kenworth Mexicana’s T680 page lists the PACCAR MX-13 at 405 to 510 hp and 1450 to 1850 lb-ft as standard and the Cummins X15 at 400 to 550 hp and 1550/1650 to 1850 lb-ft as an option, both “Euro VI”. Its spec sheet of 30 August 2024, which states compliance with “EURO 6”, instead gives the Cummins X15 at 400 hp and 1650 lb-ft as the engine and lists among the options the MX-13 from 405 hp and 1,450 lb-ft to 510 hp and 1850 lb-ft, the X15 from 400 hp and 1,650 lb-ft to 550 hp and 2,050 lb-ft, and the Cummins X12N at 400 hp and 1,450 lb-ft. The two Mexican documents name different standard engines and different top torques for the X15. The sheet’s engine equipment includes an engine brake, a Horton variable-speed fan hub, a radiator with 1456 square inches of frontal area and an 18.7 CFM air compressor, with 37.4 CFM compressors for Cummins engines and 25.9 or 37.4 CFM Wabco compressors for PACCAR engines as options.

Transmission

The PACCAR TX-12 is the standard gearbox on Kenworth’s US page. PACCAR’s sheet gives it 12 forward and 2 reverse gears, a torque capacity of 1,850 lb-ft, a system weight of 657 lb, 16 pints of oil with an oil-change interval of 750,000 miles, a maximum operating weight of 110,000 lb and an 8-bolt bottom power take-off rated at 95 hp.

Kenworth introduced the 18-speed PACCAR TX-18 and TX-18 PRO on 15 February 2022 for the T680, T880 and W990 with MX-13 and MX-11 engines, rated to 510 hp, 1,850 lb-ft and a gross combination vehicle weight of 140,000 lb. The TX-18 has three reverse gears and the TX-18 PRO six; both carry an 8-bolt bottom and a 4-bolt rear power take-off with a combined 160 hp at 1,400 rpm, and both come standard with Kenworth’s column-mounted, right-hand shifter. Kenworth gives maintenance intervals of 500,000 miles or five years on-highway and 250,000 miles or three years in vocational use. PACCAR’s sheet gives ratios from 14.32 in first to 0.7 in eighteenth, an overall spread of 20.46, 25.4 pints of oil and system weights of 808 lb (TX-18) and 813 lb (TX-18 PRO). On 27 May 2025 Kenworth made the TX-12 PRO, which it describes as designed for on- and off-highway applications such as dump, plow and tanker work, available with the MX-13 in the T680, for MX-13 ratings up to 455 hp and 1,650 lb-ft and 70,000 lb gross combination vehicle weight, with a combined 95 hp of power take-off capacity and a 250,000-mile oil interval. Kenworth and PACCAR call all of these automated transmissions; how such gearboxes work is covered in automated manual transmissions.

In Mexico the two documents differ: the product page lists a PACCAR 12-speed automated gearbox as standard and Eaton 10, 12, 13 and 18-speed manual and automated gearboxes as options, while the 2024 sheet lists the Eaton FRO16210C 10-speed with a 15.5-inch Eaton clutch rated at 1,700 lb-ft as the gearbox, and the Eaton boxes and PACCAR 12 and 18-speed automated gearboxes among the options.

Axles, suspension and brakes

The standard rear axle on Kenworth’s US page is the PACCAR DX-40 tandem, which the brochure describes as a high-efficiency 6x4 drive axle. PACCAR’s sheet rates it at 40,000 lb gross axle weight on the tandem and 80,000 lb gross combination weight, with ratios from 2.47 to 3.70 and torque ratings of 1,650 lb-ft straight and 1,850 lb-ft multi-torque; it lists a pinion thru-shaft design, a driver-controlled forward-axle differential lock and up to 150 lb of weight saving. What an axle ratio does is explained in axle ratios and final drive. No Kenworth document opened prints a list of wheel formulas for the diesel T680.

Kenworth Mexicana’s 2024 sheet lists the chassis components with their ratings in thousands of pounds (klb):

• Front axle, standard: Meritor MFS13 Plus 13.2 klb, Bendix RSD HP-ES 16.5 x 5 in brakes, variable-section leaf springs and Sheppard power steering, all 13.2 klb.
• Front axle, options: Meritor and Dana axles from 12 to 14.6 klb; Bendix or Meritor 16.5 x 5 in brakes and Bendix disc brakes at 14.6 klb; TRW power steering at 13.2 and 16 klb; AG130 air suspension at 13.2 klb.
• Rear axle, standard: Meritor MT40-14X4 at 40 klb, Bendix RSD 16.5 x 7 in brakes rated 46 klb with ABS 6S/6M, automatic traction control and electronic stability, and Kenworth AG400 air suspension at 40 klb.
• Rear axle, options: Meritor and Dana axles from 40 to 52 klb or the PACCAR axle at 40 klb; Kenworth and Hendrickson air suspensions from 40 to 46 klb; Bendix ES 16.5 x 7 in brakes up to 52 klb or 16.5 x 8.625 in at 46 klb, Meritor 16.5 x 7 in brakes up to 52 klb and Bendix disc brakes at 46 klb; Wabco ABS 4S/4M or 6S/6M with traction and stability control.
• Tyres and wheels: Pirelli R89 11R24.5 16-ply tyres on Accuride 24.5 x 8.25 in steel wheels as standard; 22.5 and 24.5-inch tyres of 14 and 16 plies and Kenworth, Alcoa and Accuride aluminium wheels as options.

Kenworth Mexicana’s product page differs on the standard rear axle, listing a PACCAR 40K lbs axle in standard and mid track with Kenworth 40K to 46K suspension, and Dana and Meritor axles of 40K to 46K lbs as options. The Body Builder Manual’s rear-suspension table gives the Kenworth AG400 a ride height of 9 inches. On 10 December 2025 Kenworth made the Bendix Intellipark electronic parking brake an available option on its heavy- and medium-duty models, with rollaway mitigation, Smart Unpark and, on towing models, automatic trailer brake release.

Frame and tanks

The Mexican sheet lists a heat-treated frame rail of 10-5/8 x 5/16 inches with a yield strength of 120,000 psi and a resisting bending moment of 1,776,000 in-lb, and as an option a 10-3/4 x 3/8-inch rail with 2,132,000 in-lb; the Body Builder Manual’s frame-rail table gives 1,776,000 in-lb for the first and 2,134,000 in-lb for the second. Partial and full inserts, Huck frame fasteners and Holland, Jost and Fontaine fifth wheels are listed. The standard fuel tank on the Mexican sheet holds 378 litres, under the cab on the right, with a 76-litre DEF tank; aluminium tanks of 22 and 24.5 inches in diameter are offered in capacities of 212, 227, 284, 378, 511, 545 and 568 litres, and a 102-litre DEF tank. No US document opened gives tank volumes for the current T680, and no document opened gives a kerb weight or a gross weight rating for the diesel T680.

Safety and driver-assistance systems

Kenworth’s US page lists the Bendix Fusion system, with a forward-looking camera and a bumper-mounted radar, for adaptive cruise control with Stop and Auto Go, autonomous emergency braking including multi-lane braking, Highway Departure Braking and lane departure warning; Predictive Cruise Control; radar side object detection on the passenger side; tyre pressure monitoring; Lane Keeping Assist with Torque Assisted Steering; and DigitalVision Mirrors. Torque Assisted Steering adds an electric motor to the hydraulic steering gear, varies assistance with speed and has three driver-selectable levels. Kenworth’s release of 11 March 2025 groups them into three packages for the T680: ADAS, with the latest Bendix Fusion including pedestrian autonomous emergency braking, High Beam Assist and stationary vehicle braking, Predictive Cruise Control, Bendix Blindspotter side object detection and tyre pressure monitoring; ADAS PRO, which adds Lane Keeping Assist with Torque Assisted Steering; and ADAS PREMIER, which adds the DigitalVision Mirrors. Kenworth’s release of 7 November 2023 describes the Stop and Auto Go function, which can bring the truck to a stop behind a lead vehicle and pull away again, and Highway Departure Braking to Zero.

The DigitalVision Mirrors pair cameras on the mirror housings with high-definition displays on the A-pillars, 12.3 inches on the driver’s side and 15 inches on the passenger side, with infrared night vision, automatic trailer tracking and camera defrosting below 43°F; Kenworth claims an “up to 1.5% fuel economy benefit with smaller mirror design”. Kenworth Mexicana’s 2024 sheet lists as options the Wabco OnGuard Active collision mitigation and OnLaneAlert lane departure systems, the Bendix Wingman Fusion collision mitigation system, Bendix side object detection, tyre pressure monitoring and the Rolltek protection system in the driver’s seat.

Battery-electric T680E

On 12 February 2020 Kenworth announced a collaboration with Meritor on the electric powertrain of the T680E, then planned as a short-hood day cab in 4x2 and 6x4 tractor form and as a 6x4 straight truck, with 100 to 150 miles of range. Kenworth’s release of 5 January 2022 describes it as a 6x4 day-cab tractor or straight truck with an 82,000 lb gross vehicle weight rating, 536 hp continuous and up to 670 hp peak power, 1,623 lb-ft, a top speed of 65 mph, an estimated range of 150 miles, a CCS1 charge port, a full charge in about three hours and Meritor’s Blue Horizon 14Xe tandem electric powertrain; Kenworth reported in June 2022 that a T680E for King County had rolled out of its Renton plant in Washington. Kenworth Mexicana handed over the first T680E in Mexico in November 2023. Its releases give the same 536 and 670 hp, a start on a 25% gradient at 36 tonnes gross combination weight, and a range of 250 km (November 2023) or 240 km (March 2024, and on its T680E page); the release of 14 November 2023 names the electric axles as built by Accelera by Cummins, while the product page names a Meritor electric drivetrain. Its zero-emission page gives a gross vehicle weight of 24 to 37 tonnes and a recharge in 3 hours.

At ACT Expo on 28 April 2025 Kenworth unveiled the Next Generation T680E, with a PACCAR-integrated ePowertrain: a central-drive eMotor with an integrated 3-speed transmission, lithium iron phosphate batteries, and day-cab tractor and straight-truck versions in 6x4. The release gave it as available for order in the US and Canada, with customer deliveries scheduled to begin later in 2025; no document opened reports deliveries.

On the sheet, two, three or four battery strings hold 250, 375 or 500 kWh, for estimated ranges of 100, 150 or 200 miles, and charging is by a 350 kW DC fast charger, with an optional 19 kW AC charger; the release names a CCS1 DC fast charger and says the truck can charge to 90% in approximately two hours. The sheet adds a system voltage of 650 V, an eMotor weight of 847 lb, a minimum wheelbase of 190 inches and electric power take-off sockets of 25 kW and 150 kW. The release offers the 500 kWh truck “up to 82,000 lb. gross vehicle weight ratings (GVWR)”, while the sheet gives “56,000 GVWR & 82,000 GCWR”. PACCAR’s own ePowertrain page, which names no truck model, lists the powertrain with up to five packs and 625 kWh.

Hydrogen fuel-cell T680 (T680 FCEV)

On 2 May 2023 Kenworth announced that it would begin production of a T680 fuel-cell electric vehicle with Toyota fuel-cell technology, with initial customer deliveries planned for 2024 and series production in 2025, and that its dealers in the US and Canada were accepting deposits. Kenworth gives the truck Toyota’s 310 kW dual motor assembly, providing 415 hp continuously at a gross combination weight rating of 82,000 lb, the Toyota Gen 2 dual fuel-cell module and a range of up to 450 miles. It followed a pilot at the Port of Los Angeles in which Kenworth customers ran 10 prototype T680 FCEVs. Kenworth’s T680 FCEV page, last captured on 15 March 2026, adds 58.8 kg of hydrogen storage, 200 kWh of high-voltage batteries, a top speed of 70 mph and a new lightweight roof fairing. On 25 May 2023 Kenworth reported a deposit from Loblaw for five trucks, and Kenworth Mexicana’s release of 14 November 2023 said it would start producing hydrogen fuel-cell trucks, developed with Toyota, in January 2025. No document opened reports series production or customer deliveries, and the T680 FCEV is not in the model menu of Kenworth’s site captured on 3 May 2026. The difference between fuel-cell and hydrogen-combustion trucks is explained in hydrogen trucks.

Source notes

Engines, in the maker’s units: PACCAR MX-13, 12.9 l, 405-510 hp and 1,550-1,850 lb-ft on Kenworth’s US page (EPA 2024 on PACCAR’s sheet), 1450-1850 lb-ft on Kenworth Mexicana’s page (Euro VI); PACCAR MX-11, 10.8 l, 355-445 hp and 1,250-1,700 lb-ft; CARB MX-13 at 455 hp and 1,650 lb-ft or 510 hp and 1,850 lb-ft; Cummins X15N natural gas, 400-500 hp and up to 1,850 lb-ft; in Mexico the Cummins X15, 400-550 hp, to 1850 lb-ft on the page and 2,050 lb-ft on the 2024 sheet. Gearboxes: PACCAR TX-12, 12 forward and 2 reverse, 1,850 lb-ft; TX-18 and TX-18 PRO, 18 forward, to 510 hp, 1,850 lb-ft and 140,000 lb GCVW; TX-12 PRO with the MX-13 to 455 hp, 1,650 lb-ft and 70,000 lb. Rear axle: PACCAR DX-40 tandem, GAWR 40,000 lb, GCW 80,000 lb, ratios 2.47-3.70. Cabs: day cab and 40-, 52- and 76-inch sleepers (76-inch mid-roof and high-roof); bumper to back of cab 124.6 in with the standard hood and 118.6 in with the MX optimized hood, bumper to back of the 76-inch sleeper 190.1 in and 184.2 in (Body Builder Manual, September 2024). Mexico 2024 sheet: 378-litre fuel tank and 76-litre DEF tank as standard, frame 10-5/8 x 5/16 in at 120,000 psi. No document opened gives a kerb weight or a gross weight rating for the diesel T680.