March 05, 2025
The powertrain is the heart of your semi-truck—the powerhouse that keeps your rig moving mile after mile. Whether you’re a fleet manager, owner-operator, or mechanic, understanding the different types of powertrains—from traditional internal combustion engines (ICE) to modern battery electric vehicles (BEV)—along with their maintenance needs and common issues, can save you time, money, and headaches. At FindItParts, we’re here to help you navigate the world of semi-truck powertrains with expert advice and the largest selection of heavy-duty truck parts online."
Diesel engines have long been the backbone of the trucking industry, prized for their unmatched fuel efficiency, incredible torque, and durability under the toughest conditions. These engines excel in heavy-duty applications, delivering the power needed to haul massive loads and tackle steep grades while maintaining better fuel economy than gasoline alternatives. Their robust construction makes them a reliable choice for long-haul trucking, often outlasting other engine types with proper care.
However, diesel engines are not without their challenges. They require meticulous maintenance to keep critical components in top condition:
Turbochargers boost power and efficiency but can suffer from lag or failure if not regularly inspected.
Fuel injectors, precision-engineered to deliver the right amount of fuel at the right time, can clog or wear out, leading to poor performance and increased emissions.
EGR systems, designed to reduce nitrogen oxide emissions, are prone to carbon buildup and require frequent cleaning to function effectively.
Additionally, diesel engines tend to have higher upfront costs compared to gasoline engines, and their performance is highly dependent on fuel quality. Using low-grade fuel or neglecting fuel filters can lead to injector clogging and other issues, underscoring the importance of investing in premium fuel and additives.
Despite these challenges, diesel engines remain a dominant force in heavy-duty trucking, offering a balance of power, efficiency, and longevity that’s hard to beat—provided they receive the care and attention they demand.
Natural Gas Engines: A Cleaner Alternative with Key Considerations
Natural gas engines, running on compressed natural gas (CNG) or liquefied natural gas (LNG), are becoming a popular choice for fleets looking to reduce emissions and lower fuel costs. These engines produce significantly fewer pollutants, such as nitrogen oxides and particulate matter, making them an environmentally friendly option. Additionally, natural gas is often cheaper than diesel, offering potential long-term savings for fleets with access to fueling infrastructure.
That said, natural gas engines come with their own set of challenges:
Unlike diesel engines, they use spark plugs for ignition, which are prone to fouling and require more frequent replacement.
Their high-pressure fuel systems demand regular inspections to prevent leaks and ensure safe operation.
While they produce less soot, extending oil life and reducing maintenance in some areas, they require specialized oil formulations to handle the unique combustion process.
On the flip side, natural gas engines have higher upfront costs compared to diesel engines, and the limited availability of fueling stations can be a hurdle for fleets operating in remote areas.CNG trucks require the attention of certified Techs and some states require certified shop buildings, That is why they are mostly only fleet trucks.Inexperienced workers could mess around and blow up the block. Despite these trade-offs, natural gas engines remain a strong option for fleets aiming to balance sustainability, cost savings, and operational efficiency.
Battery Packs: The heart of an electric engine, battery packs store the energy needed to power the truck. Proper cooling and maintenance are critical to prevent overheating and extend battery life. The battery gives an added bonus of safety, lowering the truck's center of gravity making them less likely to tip over.
Electric Motors: These motors convert electrical energy into mechanical energy, providing instant torque and smooth acceleration.
Regenerative Braking: This system captures energy during braking and feeds it back into the battery, improving efficiency and range.
Industry Insight: While electric trucks are gaining popularity, challenges like limited charging infrastructure and high upfront costs remain. However, advancements in battery technology are rapidly addressing these issues.
Hybrid Electric Engines: A Balanced Approach to Trucking
Hybrid electric engines offer a middle ground between traditional diesel engines and fully electric (BEV) trucks, combining an internal combustion engine with an electric motor and battery system. This dual-power setup provides a mix of benefits and challenges, making hybrids a versatile option for fleets exploring cleaner technologies.
One of the key advantages of hybrid engines is their improved fuel efficiency. By using regenerative braking and electric power for low-speed or stop-and-go driving, they can significantly reduce fuel consumption compared to traditional diesel engines. They also produce lower emissions, making them a greener choice for fleets aiming to reduce their environmental impact without fully committing to electric vehicles.
However, hybrid systems come with their own set of considerations:
They are more complex than traditional engines, requiring specialized maintenance and potentially higher repair costs.
While they offer better fuel efficiency, they still rely on an internal combustion engine for longer trips, meaning they don’t achieve the zero-emission benefits of fully electric trucks.
The upfront cost of hybrid trucks is higher than diesel or natural gas engines, though generally lower than fully electric options.
On the plus side, hybrids don’t face the same range limitations as BEVs, making them suitable for long-haul routes. They also don’t depend heavily on charging infrastructure, as the internal combustion engine can recharge the battery, providing greater flexibility in areas with limited charging stations.
Hybrid electric engines are a practical choice for fleets looking to transition toward cleaner technologies while maintaining operational flexibility. They offer a balance of efficiency, reduced emissions, and versatility, making them a compelling option in the evolving landscape of trucking.
Oil Changes: Use high-quality diesel engine oil and change it every 15,000 to 25,000 miles.
Fuel Filters: Replace fuel filters every 10,000 to 25,000 miles to prevent contaminants from reaching the injectors, depending on the truck.
Turbocharger Inspections: Check for signs of wear, such as oil leaks or unusual noises, and replace worn components promptly.
Pro Tip: Regularly clean the EGR valve and cooler to prevent carbon buildup, which can lead to reduced performance and increased emissions.
Spark Plug Replacements: Inspect and replace spark plugs every 50,000 to 100,000 miles, depending on operating conditions.
Fuel System Checks: Monitor fuel pressure and inspect for leaks or damage to hoses and connectors.
Oil Formulations: Use oil specifically designed for natural gas engines to handle the unique combustion process.
Lesser-Known Fact: Natural gas engines produce less heat than diesel engines, which can lead to cooler operating temperatures. Ensure your cooling system is in top condition to avoid overheating issues.
Battery Health: Regularly check battery charge levels and cooling systems to prevent overheating.
Software Updates: Keep your truck’s software up to date to ensure optimal performance and access to the latest features.
Motor Inspections: Inspect electric motors for signs of wear or damage, and replace worn components as needed.
Industry Insight: Electric trucks require less routine maintenance than diesel or natural gas engines, but battery replacements can be costly. Proper care can extend battery life and reduce long-term costs
Understanding the different types of semi-truck engines, their maintenance needs, and common issues is key to keeping your rig on the road. Whether you’re running a diesel, natural gas, or electric engine, preventive maintenance and high-quality parts are essential for optimal performance and longevity.
At FindItParts, we’re your trusted partner for all your heavy-duty truck parts needs. From fuel injectors to battery packs, we’ve got the parts and expertise to keep your engine running smoothly. Visit FindItParts.com to shop premium parts and accessories today.
