Have it all with the 2024 X15 and X12 powertrain lineup.
With a focus on uptime, total cost of ownership and ease of operations, the Cummins heavy-duty truck engine platforms bring you the best 15-liter and 12-liter engines yet. Starting with the most reliable 15-liter ever produced, to offering EX ratings for enhanced driver performance, the X15 and X12 give you the confidence needed to improve your business without sacrificing anything.
—Devon Simper, Operations Manager for Savage Trucking
The Cummins X15 answers our fleet partners' needs for reliable and durable performance. Take it from Savage Trucking—the Cummins X15 engines enable their trucks to pull 129,000 pound loads at altitudes 9,000 feet above sea level across the American West.
Watch how Cummins pushes their fleet to maximize performance and efficiency.
X15N
Discover the industry’s first big bore natural gas engine that delivers solutions for a range of long-haul heavy-duty truck applications. With power ratings up to 500 hp and torque up to 1850 lb-ft, this engine will revolutionize transportation and your application needs.
Power under weight-sensitive applications
X12 (2024)
The X12 is designed to give weight-sensitive applications maximum payload. And at just 2,050 lbs., the X12 is at least 150 lbs. lighter than the lightest competitive 11L engine, yet it still delivers powerful performance from 350-500 HP and 1250-1700 lb-ft Torque. With the response and power of larger displacement engines, the X12 delivers the performance drivers desire while maximizing efficiency for every job.
Learn about tomorrow - today
The 2027 X15
Introducing the 2027 X15 engine. The next step in the Cummins HELM™ 15-liter platform. Offering up to 605 hp and 2,050 lb-ft torque, this engine demonstrates our continued commitment to the evolution of internal combustion technology.
X10
Introducing the new Cummins X10, a next generation engine that brings a state-of-the-art platform to medium-duty, heavy-duty, vocational, and transit bus applications, launching in North America in 2026. This engine is uniquely positioned to replace both the L9 and X12.
Choosing the right heavy-duty truck engine
Cummins diesel engines are favorites in the North American heavy-duty truck market. Drivers, owner/operators, and fleet managers agree: Cummins engines are among the most powerful and reliable Class 8 truck engines on the road.
Heavy-duty truck engines by use case and primary benefit
| Use case | Primary benefit | Engine recommended |
|---|---|---|
| Long hauls | Efficiency | X15 Efficiency Series |
| Multi-purpose | Continual access to peak horsepower | X15 Productivity Series |
| Premium linehaul | More than 500 HP | X15 Performance Series |
| Weight-sensitive vocational or regional haul | Maximum payload | X10 Engine |
Heavy-duty truck fleet optimization tools
Make confident decisions faster with tools that simplify your journey
Frequently asked questions
Heavy-duty truck engines are usually diesel or natural gas engines designed for Class 8 semi-trucks used in demanding commercial applications. These engines are built to deliver high horsepower to meet needs such as maximum payload capacity, long-haul efficiency, and continual access to peak power. These powerful engines are engineered for use cases ranging from weight-sensitive vocational and regional haul work to multi-purpose, long-distance commercial trucking.
The best heavy-duty truck engine is subjective and highly depends on your use case. We recommend the following based on the intended use:
- Long-haul efficiency: X15 Efficiency Series
- Multi-purpose with continual access to peak horsepower: X15 Productivity Series
- High horsepower (500+ HP): X15 Performance Series
- Maximum payload (weight-sensitive vocational or regional haul): X12 engine
To choose the right heavy-duty truck engine, please consider the needs for your use case:
- Long-haul efficiency: Choose the X15 Efficiency Series
- Multi-purpose with continual access to peak horsepower: Choose the X15 Productivity Series
- High horsepower needs (500+ HP / premium linehaul): Choose the X15 Performance Series
- Maximum payload (weight-sensitive vocational or regional haul): Choose the X12 engine
The following fuel types are available for heavy-duty truck engines:
- Diesel: A relatively cheap fuel that’s widely available and performs well with durable and reliable engines that provide all the torque needed for heavy-duty applications.
- Renewable Diesel (HVO): A fuel made from vegetable oils and animal fats. It can often be used as a drop-in replacement for diesel with no engine modification with net CO2 emissions typically 70% lower than diesel.
- Biodiesel: A renewable fuel most often blended with diesel. B20 blends balance cost and emissions and can generally be used with no engine modifications (always check with the manufacturer and truck manual before using).
- Natural Gas (CNG/LNG): A fuel that can be used in either compressed or liquefied form. Natural gas performs similarly to diesel with lower CO2 and reduced NOx and particulate emissions.
- Renewable Natural Gas (RNG): A fuel produced from biogas captured from organic waste. RNG can help fleets reach sub-zero greenhouse gas emission levels.
- Hydrogen: Cummins is developing hydrogen internal combustion engines, including a 15-liter and 6.7-liter version for heavy-duty commercial applications.
- Battery Electric: Battery electric trucks significantly reduce operating costs due to lower fuel and maintenance expenses. With zero tailpipe emissions, they contribute to cleaner air quality and the reduction of greenhouse gas emissions. Cummins offers battery electric solutions through Accelera™ by Cummins.
Cummins heavy-duty truck engines include the X15 Efficiency Series, X15 Productivity Series, X15 Performance Series, X12, X15N, the 2027 X15, and the new X10.
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Transportation has evolved since the beginning of time. What does the future of transportation hold?
Going further, faster
Today’s medium-duty fleets are faced with a growing demand to deliver high performance while lowering environmental impact.
Low and stable natural gas prices continue to draw attention from fleets and owner-operators looking to reduce operating costs while lowering emissions.
Maximizing fluid economy in a heavy-duty diesel powertrain begins long before a new truck delivers its first load.
Summary Diesel powertrains and battery electric powertrains each offer distinct advantages depending on the application.
Summary Natural gas vehicles (NGVs) can offer commercial fleets significant fuel cost savings compared to diesel, with compressed natural gas (CNG) averaging $2.
Cummins: Bringing diesel to new frontiers We are always looking for ways to get the most out of products. We know that there are many options for diesel engines, but no other manufacturer is trusted more than our team at Cummins. Contact us today to find out all that we can provide you.
