A combustion engine forklift, also known as an internal combustion (IC) forklift, is a powered industrial truck that uses an internal combustion engine to generate power. These engines are fueled by diesel, gasoline, or liquid petroleum (LP) gas / LPG. They are the traditional workhorses of the material handling industry, prized for their power, durability, and ability to operate continuously in demanding environments.
Fuel Types
Combustion engine forklifts are categorized by their fuel source, with each offering a distinct set of advantages.
Fuel Type Best For Key Advantages Key Disadvantages
Diesel Heavy outdoor use, ports, construction sites, lumber yards Maximum power, high torque for heavy loads, excellent fuel efficiency, low RPM torque Highest emissions, noisy, only suitable for outdoor use
LPG (Liquefied Petroleum Gas) Mixed indoor/outdoor use with ventilation, warehouses without charging infrastructure Cleaner than diesel, lower emissions, can be used indoors with proper ventilation Lower power than diesel
Gasoline Light outdoor use, occasional applications Familiar and easy to refuel Least efficient fuel type, produces high emissions
Applications: Where Combustion Engine Forklifts Excel
Combustion engine forklifts are the preferred choice for a specific set of demanding applications.
Outdoor and Rough Terrain
These forklifts are primarily intended for outdoor use. They are ideal for rough terrain, lumber yards, construction sites, and any environment with uneven surfaces. Their high ground clearance and powerful engines allow them to navigate challenging conditions that would stop an electric truck.
Heavy-Duty and Continuous Operation
IC forklifts are essential for heavy loads over 5 tons and for operations requiring continuous 24/7 use without the downtime needed for battery charging. They are the standard for ports, steel yards, and other heavy industrial settings.
Mixed Indoor/Outdoor Use
While primarily for outdoor use, modern LPG forklifts are now so low in emissions that they are also suitable for indoor use, provided there is adequate ventilation.
Advantages of Combustion Engine Forklifts
Lower Upfront Cost
IC forklifts generally have a lower initial purchase price compared to electric models, especially those with lithium-ion batteries. In some cases, the purchase cost can be up to 20% lower than an equivalent electric model.
Fast Refueling
Refueling an IC forklift takes less than five minutes, providing near-zero downtime compared to the hours required to charge a battery. This makes them ideal for multi-shift operations.
High Power and Performance
IC forklifts offer high performance, maximum power, and excellent torque, which is crucial for handling heavy loads and navigating inclines.
No Charging Infrastructure
They require no battery chargers or charging stations, eliminating the need for electrical infrastructure and the associated costs.
Disadvantages of Combustion Engine Forklifts
Higher Operating Costs
IC forklifts have higher long-term operating costs. Fuel costs for diesel can range from $2.80 to $3.50 per hour, while electric equivalents cost just $0.30 per hour. Diesel forklifts also require more frequent and expensive maintenance due to their complex engines and exhaust systems.
Emissions and Noise
Combustion engines produce harmful exhaust fumes, including carbon monoxide and nitrogen oxides, and are significantly noisier than electric trucks. This makes them unsuitable for indoor use without proper ventilation and less aligned with sustainability goals.
Higher Maintenance
With more moving parts, IC forklifts require regular servicing, including oil and filter changes, which increases both downtime and costs.
2026 Market and Regulatory Landscape
Market Share
Despite the rapid growth of electric forklifts, internal combustion engine-powered trucks still lead the market, holding around 56.5% of the global market share in 2025. The global forklift market is projected to grow from USD 40.89 billion in 2025 to USD 66.95 billion by 2032.
Regulatory Pressures
Combustion engine forklifts are facing increasing regulatory pressure, particularly in markets like California. New regulations are being introduced to phase out internal combustion engine (ICE) forklifts in favor of zero-emission alternatives.
January 1, 2026: A critical compliance date has passed, restricting the sale of new Class 4 ICE forklifts.
January 1, 2029: Restrictions will extend to Class 5 forklifts with a rated capacity of 12,000 pounds or less.
Through 2038: Fleets are required to phase out most existing LSI forklifts over time.
Summary
Combustion engine forklifts are powerful, durable, and reliable workhorses essential for heavy-duty outdoor applications and continuous operations. However, they come with higher long-term costs, significant emissions, and increasing regulatory pressure. While they remain a strong choice for specific needs, the industry is clearly shifting towards electric alternatives, which now account for over 70% of new sales. The decision to choose a combustion engine forklift should be based on a careful analysis of your specific operational requirements, including terrain, load capacity, usage intensity, and budget for both purchase and ongoing operation.