Test Drive: Cummins X12 Diesel Engine Version 2.0
Autocar Trucks to Receive First Cummins X12 Engines
Autocar Trucks is the first North American OEM to introduce Cummins' new X12 engine to the refuse market. Autocar claims the engine will enable customers to haul more than 700 pounds additional payload while delivering almost $11,000 in fuel savings over the life of a truck.
Autocar Trucks will be the first North American refuse truck manufacturer to offer the new Cummins X12 engine. The 11.8-liter X12 diesel engine will be offered in ACX refuse trucks beginning in October when Cummins starts full production of the X12 at its Jamestown, N.Y. facility. Autocar will begin accepting orders for X12-powered trucks in June.
According to Autocar, the X12 will net customers an additional 733 pounds of payload compared to the previous engine, the ISX12. The weight saving is achieved through an innovative sculpted block design, as well as weight reduction in the after-treatment system, power take-off, and other components. The X12 also offers improved low-speed torque, even with similar horsepower ratings. At 2,050 pounds dry weight, the X12 is the lightest engine in the market compared to existing 11-, 13-, and 15-liter engines.
Integration of the X12 offers lower operating costs due to extended maintenance intervals, 25% fewer parts, and a 6% improvement in fuel economy. The fuel savings alone equates to $10,800 over the life of a typical garbage truck at current diesel prices, Autocar says.
"Autocar is focused on bringing innovations to the market with real, tangible benefits to our customers," said Jim Johnston, president of Autocar. "This new engine puts more cash in our customers’ pockets, plain and simple. We’re gratified that Cummins trusts us to bring the X12 engine to the refuse market first."
Cummins introduced the X12 to North America in August 2016, but development work began in 2013 in close collaboration China's Foton Motor Co. There it's known as the ISG. The version of the engine we will see here has been substantially re-engineered to meet North American emissions rules and customer expectations.

"We are excited to continue our partnership with Autocar through the introduction of Cummins’ next generation X12 diesel engine in Autocar’s ACX chassis" said Brett Merritt, vice president of Cummins’ on-highway engine business. "Autocar is a key player in the North America refuse market and this introduction will further our current collaboration across natural gas and diesel platforms."
The X12 engine was tested in diverse terrain across the United States and Canada. Over two million miles of field testing was conducted across the full spectrum of applications, Cummins says. Drivers will notice smoother operation with fewer downshifts and even more responsive torque at low speeds.
“Built around improved uptime and reliability, the X12 will be in prime position to support Autocar’s vision of ‘Always Up’”, continued Merritt.
Autocar will offer the X12 across all Class 8 severe-duty vocational applications.
More Equipment

Kenworth Names Peter Ahrens General Manager
Leadership changes at Kenworth take effect July 1 as the OEM promotes two longtime Paccar executives to key management roles.
Read More →
Hino Adds Electric Class 6/7 Truck
Hino says the Le Series is an important step in the company's efforts to reduce environmental impact and support its customers’ sustainability goals.
Read More →
ACT Expo 2026: Highlights in Photos
The 2026 Advanced Clean Transportation Expo featured a broad range of commercial vehicle technologies, from EVs to autonomous trucks to the latest diesel and alternative-fuel engines.
Read More →
Hendrickson Debuts Electraax E-Axle for Medium-Duty Trucks
Developed with Driventic, Hendrickson's new integrated e-axle is designed to improve efficiency, reduce weight, and extend range in Class 6-7 EV applications.
Read More →
Peterbilt Unveils Freedom 250 Special Edition Model 589
Peterbilt’s just-announced limited-run patriotic Model 579 tractor celebrates America’s 250th birthday with custom styling and premium features.
Read More →
Mack Unveils EPA 2027-Compliant MP13 Engine With More Power, Better Fuel Economy
Along with unveiling its EPA 2027-compliant MP13 engine, Mack outlined powertrain changes across its Class 6-8 lineup, including new Cummins-based X10 engines.
Read More →
Kodiak and Roehl Transport Launch Autonomous Route Between Dallas and Houston
Kodiak AI and Roehl Transport have begun autonomous freight operations on a regular Dallas-Houston route, marking another step toward Kodiak’s planned driverless launch by the end of 2026.
Read More →
Autonomous Trucks at ACT Expo 2026
Autonomous trucks commanded a lot of attention from attendees at ACT Expo this year. Check out this photo gallery.
Read More →
How Volvo’s New D13 Engine Meets EPA 2027 Emissions Without Sacrificing Power or Fuel Efficiency
Volvo says advances in combustion and aftertreatment helped its new EPA 2027 D13 engine avoid the fuel-economy penalties many once expected from tighter NOx emissions limits.
Read More →
Fleet Advantage TLDI Highlights Rising Costs of Aging Fleet Equipment Amid Higher Diesel Prices
Fleet Advantage’s latest Truck Life Cycle Data Index shows fleets operating older Class 8 trucks could face significantly higher costs as diesel prices rise, while newer 2028 equipment may deliver savings of more than $12,000 per truck annually.
Read More →
