NACFE Discusses Truck Emissions Tech in New White Paper

NACFE: Navigating the “Messy Middle” in Trucking – The Shift to Cleaner Powertrains

A new white paper from the North American Council for Freight Efficiency (NACFE), Navigating the Messy Middle: The Move to More Sustainable Trucking, explores how trucking fleets are transitioning to cleaner powertrains. NACFE’s 2023 Thought Leadership report, The Messy Middle: A Time for Action, also covers this topic, highlighting both challenges and opportunities.

These reports explain powertrain choices, evolving regulations, and infrastructure issues. They also offer opinions on industry trends, including sustainability efforts and government policies. NACFE believes the future of trucking will be battery-electric and hydrogen fuel cell vehicles by 2050. However, the shift will take time, and fleets must make smart decisions about what to do now.

What Is the “Messy Middle” According to NACFE?

The Messy Middle describes the time between diesel being the main fuel and a future where zero-emission trucks take over. Right now, many different powertrain options are available. This gives fleets choices, but it also makes decisions more complicated.

The word “middle” means there was a beginning and there will be an end. Diesel has been the main fuel for over 100 years. In the future, NACFE expects electric and hydrogen trucks to dominate. The word “messy” means fleets must sort through many choices, trying to figure out which works best for them.

NACFE says fleets will likely take one of two paths:

1. Move straight from diesel to zero-emission trucks when the timing is right.
2. Use other fuels as a short-term solution, such as natural gas, hybrids, or renewable diesel.

However, many obstacles stand in the way. The high price of new trucks, the lack of charging and fueling stations, and uncertain rules and regulations make this shift harder.

Powertrain Options for Fleets

Fleets now have more options than ever before. Each powertrain has benefits and challenges.

1. Diesel

• Diesel is still the most common fuel in trucking.
• Newer diesel engines burn fuel more efficiently and produce fewer emissions.
• But diesel still creates pollution, and new rules will likely keep pushing for cleaner alternatives.

2. Renewable Diesel

• Made from biomass, this fuel can be used in any diesel engine without changes.
• It creates less pollution but is more expensive and harder to find than regular diesel.

3. Biodiesel

• Produced from plant oils, biodiesel is usually mixed with fossil diesel in small amounts.
• It reduces emissions, but high blends can cause engine issues in cold weather.

4. Compressed Natural Gas (CNG) & Renewable Natural Gas (RNG)

• CNG burns cleaner than diesel but has fewer fueling stations.
• RNG is made from organic waste, so it has a lower carbon footprint.
• However, RNG is not available in large enough amounts to replace diesel yet.

5. Hydrogen Internal Combustion Engines (ICE)

• These engines burn hydrogen instead of diesel, producing no carbon emissions.
• But hydrogen is expensive, and fueling stations are rare.

6. Hybrid Powertrains

• Hybrids combine an engine with battery power to improve fuel efficiency.
• They work well for stop-and-go driving, but offer little benefit for long-haul trucking.

7. Battery Electric Vehicles (BEVs)

• These trucks produce zero emissions and use electricity as fuel.
• However, charging infrastructure is still growing, and battery costs remain high.

8. Hydrogen Fuel Cell Electric Vehicles (HFCEVs)

• Hydrogen fuel cells have a longer range than battery-electric trucks and refuel faster.
• But hydrogen fuel is costly, and there are very few refueling stations.

Challenges Fleets Face

Switching away from diesel is not easy. NACFE points out some major challenges:

1. High Costs – New trucks cost more than diesel models. Charging and fueling stations also need big investments.
2. Infrastructure Problems – Few charging stations and hydrogen pumps exist right now.
3. Unclear Regulations – Emission laws keep changing, making it harder to plan ahead.
4. Operational Factors – Some powertrains work better for certain jobs. Route length, weight, and climate all matter.

NACFE’s “Run on Less – Messy Middle” Study

To help fleets understand their options, NACFE is launching Run on Less – Messy Middle in September 2025. The event will track 10 fleets using a mix of battery-electric, hydrogen fuel cells, RNG, renewable diesel, and hybrids.

This study aims to collect real-world data and help fleets decide which powertrain works best for their needs.

How Fleets Can Choose the Right Powertrain

Fleets must think about several key factors before choosing a new powertrain:

• Type of Haul: Is the truck used for long-haul, regional, or local deliveries?
• Fuel Costs & Supply: Some fuels cost more or are harder to find in certain areas.
• Regulations: Laws may require cleaner trucks in the future.
• Customer Expectations: More shippers want lower-emission transportation.

Some fleets may start by using cleaner fuels like biodiesel or hybrids before switching to zero-emission vehicles. Others may move straight to battery-electric or hydrogen if they have the right infrastructure.

Looking Ahead

The trucking industry is moving toward cleaner powertrains, but fleets must start planning now. Waiting for one perfect solution is not a good option.

Fleets should test different solutions to find what works best for their business. Whether improving diesel efficiency, experimenting with alternative fuels, or investing in electric trucks, every step counts.

NACFE’s research shows there is no single answer for all fleets. Each company must find the right mix of powertrains based on its budget, operations, and sustainability goals.

The transition to zero-emission trucking seems to be happening. Fleets that navigate the Messy Middle wisely will be better prepared for the future.


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