Your fuel choices can help you win bids with sustainability requirements.


By Steve Klein

Many fleets are in the midst of bid season this time of year. With private and public sector organizations placing a growing importance on making environmentally responsible decisions, institutions that hire fleets are looking more closely than ever at their suppliers’ sustainability efforts.

Let’s look at some tips for fleets seeking to convey strong sustainability data in bid responses. Then I’ll break down some common alternative fuel options that can help you get there.

Track and tout your data.

Organizations issuing RFPs are starting to ask for more and more data, both emissions-related and related to the fuel itself. If you have the numbers to prove that you’re a lower-carbon option, take the opportunity to show them how that could benefit their business. If you aren’t tracking this kind of information yet, talk to your fuel partner to see if they can help.

Sell yourself as a sustainability provider… right now.

A lot of attention is being paid to the development of electric trucks. That’s fine, but the infrastructure and technology are just not there yet for trucking applications and won’t be for a while. If you’re waiting for electric vehicles before getting on board with sustainability, you’re losing time and money. For 2022 and, really, the next few years, using drop-in solutions in your existing vehicles will help lower fleet emissions immediately.

Take advantage of the financial benefits of cleaner fuels.

Sustainability is growing in importance, but many RFPs still go to the lowest responsible bidder. Explore fuels that allow you to reduce your emissions and be more competitive with price. This means not just what you pay per gallon but also whether you need to upgrade your trucks to run on it, make changes to fueling infrastructure, search hard for supply and other issues. Maintenance can also be a factor. On top of all that, you may be able to take advantage of incentives like the federal Biodiesel Tax Credit.

Don’t be afraid to use multiple fuels to achieve your goals.

There is no silver bullet solution when it comes to which fuel a fleet should use. For example, a fleet in the Midwest might use higher biodiesel blends. A national fleet might buy a renewable diesel and biodiesel blend for its West Coast operations (because it is more widely available there) but primarily use biodiesel blends elsewhere and test out a handful of electric or compressed natural gas (CNG) trucks. The point is, an integrated energy management approach is worth considering—and a good fuel partner can help you determine the right solution and explain the advantages of it in your bids. Speaking of finding the right mix, let’s dive into the most common and sustainable options, including their carbon intensity (CI) scores from the California Air Resources Board (CARB).* This “well to wheels” approach considers direct effects like fuel production and usage and indirect effects like land use. The lower the score, the better. For comparison, petroleum diesel’s score is 100.5.



Electric trucks are still in the early stages of development. While it is possible to convert an existing vehicle, switching to electric almost always involves buying a new vehicle. Charging infrastructure is also required, which is currently seen as the main barrier to adoption, particularly in trucking.

Fully electric vehicles do not generate tailpipe emissions. With any fuel, however, it’s important to also consider the full life cycle: What goes into its production, delivery and end use? CARB’s standard value for electricity from the California grid is 82.9.


Compressed Natural Gas

Natural gas is a fossil fuel comprised primarily of methane. In transportation, CNG is produced by compressing the gas to less than 1% of its volume at standard atmospheric pressure. It can also be used in a liquid form, known as liquefied natural gas.

Fleets would need to either convert vehicles to run on CNG or buy new vehicles. Fueling occurs with specialized equipment and, as with electric vehicles, fleets with their own fueling locations would have to install new infrastructure. CARB gives fossil-based CNG a CI score of 79.2.



Biodiesel is made from renewable resources, including used cooking oil, waste animal fats and vegetable oils. Fleets can run on biodiesel blends without making changes to vehicles or fueling infrastructure. Some fleets have even started running on 100% biodiesel with a simple, affordable modification to their trucks.

Compared with ultra-low sulfur diesel (ULSD), biodiesel has higher cetane, leading to more complete combustion, and more lubricity, which reduces wear and damage to fuel pumps and injectors. Also, its cleaner burn sends less particulate matter to diesel particulate filters, minimizing the impact on those emissions control devices.

Among liquid fuels, biodiesel has repeatedly received the lowest CI score from CARB. Its average CI score as of October 29, 2021, the most recent available, is 28.5.


Renewable Diesel 

Renewable diesel is made from the same feedstocks as biodiesel, but the feedstocks are reacted with hydrogen during the production process. It can be used in most diesel engines without any modifications.

Like biodiesel, it has higher cetane than petroleum diesel and lower sulfur content and aromatics. Its Cloud Point, which is the temperature at which a fuel appears cloudy, is lower than biodiesel’s. Renewable diesel is often right behind biodiesel in CARB’s CI scores. Its current average score is 38.7.


Blend of Biodiesel and Renewable Diesel

Traditionally, biodiesel has been blended with petroleum diesel, and renewable diesel has been used by itself. But biodiesel and renewable diesel can also be combined to give users the benefits of each fuel. No equipment changes are necessary.

Blending renewable diesel and biodiesel results in a fuel that is stronger than the individual components. The concept is similar to alloys, in which different metals are combined to make the end product better than the beginning materials.

Biodiesel is more effective than renewable diesel at reducing several key pollutants, including particulate matter, carbon monoxide and total hydrocarbons. Renewable diesel, meanwhile, generates greater reductions of NOx. Blending them together results in a fuel with significantly lower emissions than petroleum diesel. CARB has not assigned a CI score to the blend yet; but using the same methodology, Renewable Energy Group has calculated that an 80/20 blend of our best-in-class renewable diesel and biodiesel would have a CI score of 17.6.


Ultimately, what’s best for a fleet depends on its unique circumstances.

*CARB CI score information (; quarterly reporting tool (


Steve Klein is senior manager, marketing, at Renewable Energy Group, Inc. REG is North America’s largest producer of biodiesel and an industry leading producer of renewable diesel. REG solutions are alternatives for petroleum diesel and produce significantly lower carbon emissions. In 2019, REG produced 495 million gallons of cleaner fuel delivering over 4.2 million metric tons of carbon reduction. Klein can be reached