Jan 7th 2025
Kenworth remains to be one of the leading brands when it comes to manufacturing semi-trucks that provide exceptional performance and driver comfort. In this article, we’ll explore when the Kenworth T680 came out on the market and how it revolutionized efficiency and comfort in trucking.
When Did the Kenworth T680 Come Out?
Kenworth announced the production of the Kenworth T680 at the 2012 Mid-America Trucking Show in Louisville, as it was meant to replace the T660 and T700 units. However, due to EPA13 emission requirements, the model wasn’t released until 2013.
The other Class 8 releases that year focused on fuel economy through aerodynamics. On the other hand, Kenworth concentrated on offering better power efficiency by improving the T680’s powertrain. The flagship variants feature an EPA2021 PACCAR MX-13 Engine with TruckTech+ Remote Diagnostics and Over-the-Air Updates, which give users intelligent driving capabilities. The T680 also comes in a cheaper variant, manufactured with a PACCAR MX-11 engine.
Aside from these configurations, the T680 has an all-new cab design with a 2.1-meter width, state-of-the-art construction, and stamped aluminum base. Kenworth continues to manufacture the T680, albeit in a slightly configured iteration compared to its original release. The company calls the new units the T680 Next Generation, which come with a more high-tech dashboard, a taller grille, and streamlined cab design.
How Was Kenworth T680 Created?
The design of the Kenworth T680 we know today can be traced to several models: the T660, T880, and W990. To understand how the unit achieved its maximum comfort and efficiency, let’s go through these units one by one:
Kenworth T660
In 2007, Kenworth released the T660, which replaced the classic T600. The model graced a similar look to its predecessor. However, it was manufactured with better aerodynamics and an engine that will meet the new emission requirements for Class 8 conventional cab trucks.
Furthermore, the T660 also came with GPS navigation, better driver info displays, multiplexed wirings, onboard engine diagnostics, and other technological solutions that improved the overall riding performance of the unit. Despite all these impressive features, the T660 was ultimately discontinued in 2017 and effectively replaced by the T680.
Also read: Kenworth T660 Truck: A History of Efficiency and Innovation
Kenworth T880
The first Kenworth T880 was delivered in March 2014. The Class 8 semi-truck was released as a replacement for the T800. It shares a similar cab design to the T680, albeit in an 8” wider size. It also comes with a one-piece windshield and is currently available with a Cummins X15 or PACCAR MX13 engine.
The American Truck Dealers (ATD) hailed the T880 as the 2015 Truck of the Year. The organization saw how dependable the truck is for vocational use. Because of the overall rugged design of the truck, it’s usually configured to be a pickup, concrete mixer, firetruck, and delivery truck. Kenworth still manufactures the T880 to this date.
Kenworth W990
In 2019, Kenworth released the W990, an upgraded and more contemporary version of the W900L. It sports the same cab design as the T680, with a 1.5” longer hood compared to the W900L. It’s made available with PACCAR MX13 and MX11 engines and the updated Kenworth navigation dashboard. Like the T880, Kenworth still manufactures the W990.
What Made the Kenworth T680 Special?
The Kenworth T680 wouldn’t be popular among truck drivers today without its impressive engine, interior, exterior, and high-tech features. Let’s go through each of these categories:
Engine
The engine configurations of the T680 can be categorized into two: the flagship EPA 2021 PACCAR MX-13 and the optional PACCAR Mx-11.
The PACCAR MX-13 has a 12.9-liter engine with 405-510 horsepower and 1550-1850 lb-ft of torque. It’s mated with a PACCAR TX12 automatic transmission and a PACCAR DX-40 rear tandem axle. The exhaust/aftertreatment system features a right-hand under fairing DPF/SCR configuration, along with a DEF tank that provides 21 usable gallons.
On the other hand, the PACCAR MX-11 has a 10.8-liter engine with 355-455 horsepower and 1250-1700 lb-ft of torque. It has the same configuration as the MX-13 variant except for its small round DEF tank of 11 usable gallons.
Needless to say, the MX13 variant is a popular option for regional haulers and heavy-duty vocational service providers. On the other hand, the MX11 units are geared toward city use.
Utility trucks are just like any other business item–their value is weighed based on their return on investment (ROI). However, achieving a good ROI for conventional-cab trucks can be tricky–not only are they expensive, but most models also have high fuel consumption and costly repair needs.
This is why truck owners and drivers alike rejoiced when Kenworth introduced their T660 model in the market. Kenworth promised excellent fuel efficiency–and they didn't disappoint.
In this article, we'll take a look at the history of the Kenworth T660 and why it is hailed as one of the most efficient and profitable conventional cab trucks introduced to the market.
History of the Kenworth T660
To understand the development of the Kenworth T660's overall design, we'll review its history and development.
1976 Kenworth T600
Undoubtedly, one of Kenworth's most well-liked conventional-cab truck lines is the T600. The T600 was the American market's first semi-tractor created expressly for high fuel efficiency. This will not come as a surprise, though, as the T600 is Kenworth's response to the 1973 oil crisis, which significantly increased diesel and gasoline prices.
The Class 8 T600 had an aerodynamic sloped hood, set-back front axle, smaller turning radius, longer front springs for better suspension, and improved weight distribution. All these bodyworks made T600 units 20% more fuel efficient than the famous W900 and other Kenworth models. Furthermore, the lower drag design enabled the T600 to run with approximately 100 less horsepower despite full payload, further increasing its fuel economy.
Due to its popularity among businesses, Kenworth continued developing numerous variations of the T600, increasing fuel efficiency with every update.
1990 Kenworth T600A and 1995 T600B
Before moving on to the T660, Kenworth released two sub-variants of the T600. The Kenworth T600A, introduced in 1990, shared the T600's general interior and exterior. However, it also had brand-new rearview mirrors mounted in a single housing, a twin-segment grille, and curved windshields. The Aerodyne Sleeper Cab II, which first appeared in the W900 range, was its basis.
During this time, Kenworth partnered with Boeing, giving some T600A units a digital dashboard.
In 1994, the Kenworth T600B was introduced to replace the T600A. It also had a nearly identical design to the T600A, with a few adjustments made to fulfill the then-current revised conventional-cab specifications. The sleeping units of the T600B used the innovative Aerocab sleeper concept, which combined the cab and sleeper into one unit rather than two.
Despite the minor updates, the T600B won the National Award for the Advancement of Motor Vehicle Research and Development from the US Department of Transportation in 1995.
2007 Kenworth T660
The Kenworth T660 formally replaced the T600 in 2007. While it retained most features of the T600, it sported upgrades that further pushed the line's aerodynamics and fuel efficiency.
The T660 was manufactured with an updated hood and fenders to enhance its aerodynamics. These fenders are paired with composite headlamps and two-panel grilles similar to the T2000. The front axles were updated to 12,000-14,600lb, and the rear axles to 23,000-46,000lb, ensuring maximum performance and efficiency regardless of a full payload.
Most importantly, the T660 used a new diesel-powered engine from PACCAR to meet new emission requirements, boosting the model's fuel efficiency. The reported average fuel use of the T660 is 6.5 mpg at idle and 6.6 mpg while running, which is truly impressive for a Class 8 conventional-cab truck.
Aside from these changes, the T660 sleeper units retained the Aerocab sleeper format of the T600. The sleeper sizes ranged from 38-86 inches, with high-roof Aerodyne on the longest units and low-profile FlatTop on the shorter ones.
2013 Kenworth T680
Kenworth released the T680 to fulfill the EPA13 emission criteria, thereby replacing the T660. The truck is also easier to handle and maintain due to its TruckTech+ features and digital mirrors. Because of this, the model is known as the "Next Generation."
Thankfully, Kenworth carried on the T600's tradition of fuel efficiency because the T680's EPA21 PACCAR MX13 engine boosted powertrain efficiency.
Proving the Efficiency of Kenworth T660
Because of the T660 Regional Transporter model's capacity to save fuel, Kenworth sold 1,600 of them in 2011-2012. Business owners claim that a single T660 unit can provide better aerodynamic advantages, lighting features, and fuel efficiency compared to more expensive regional haulers.
The Chippewa Sand Transport company put the T600 units through a few tests to demonstrate the T660's potential for efficiency.
The most fuel-efficient model configuration was the T660 Regional Hauler with a 12.9-liter PACCAR MX engine. It had an anticipated fuel economy of 6 mpg for a 23-mile trip at an average speed of 40 mph. Sand was used to fill the unit.
By producing 6.5 mpg at idle and 6.6 mpg while moving, the T660 unit outperformed their expectations at the end of the test. It's also important to note that the tested device had yet to be broken in, so when it operates at its best, it should achieve 7 mpg.
A business using T660 in its hauling operations can save up to $325,000 a year in fuel, given that the expected diesel price is $4.2 per gallon. That amounts to more than $300,000 that can be set aside for business growth.
The company put its T660 regional haulers through additional testing, using them to transport lime, cement, fly ash, and other products over a 500-mile radius. The units maintained the same fuel efficiency.
According to Chippewa's research, the Kenworth T660 is undoubtedly one of the most effective and profitable conventional-cab trucks ever produced.
Unleash the Full Potential of Your Kenworth T660
Truck owners are well aware of the enormous impact the HVAC system can have on their day to day comfort. And the same is true for the Kenworth T660. Despite its well-proven design and fuel efficiency, an inadequate HVAC system can prevent it from operating to its full potential.
We recommend seeking a HVAC box with a stainless steel shell and an upgraded blower motor to get the most out of your T660. The new HVAC unit will operate at peak efficiency thanks to the 15% increase in CFM above OEM.
This HVAC Upgrade will help ensure owners and drivers stay comfortable while enjoying all the great features of the T660. There's no denying that Kenworth really delivered on its promise of excellent fuel economy with the T660. With the right configurations and proper maintenance, the T660 can generate a good ROI for all business owners.