How to buy renewable energy biodiesel for fleets and diesel equipment

a[data-rs-seo-link]{text-decoration:underline!important;color:#1a56db!important;cursor:pointer!important;}a[data-rs-seo-link]{text-decoration:underline!important;color:#1a56db!important;cursor:pointer!important;}

What to know before you buy renewable energy biodiesel

Renewable energy biodiesel can be a practical lower-carbon fuel option for diesel fleets, farms, generators, marine operators, and facilities that already run compression-ignition engines. The purchasing decision should start with fit, not only with the lowest price per gallon. Buyers need to choose a blend level that matches their equipment, climate, storage system, warranty terms, and emissions goals.

For many users, B5 or B20 is easier to adopt than B100 because it usually requires fewer changes to equipment and day-to-day operations. Higher-level blends can increase the renewable fuel share, but they also require closer control of cold-flow performance, fuel quality, materials compatibility, and storage practices.

This guide treats biodiesel as a procurement decision. It uses public information from the U.S. Department of Energy Alternative Fuels Data Center, the U.S. Energy Information Administration, the U.S. Environmental Protection Agency, ASTM International, and the National Renewable Energy Laboratory. For more renewable product comparisons, visit our Buying Guides.

Biodiesel basics buyers should understand

Biodiesel is a renewable, biodegradable diesel substitute made from vegetable oils, animal fats, or recycled cooking grease. In its pure form, it is called B100. Most buyers use biodiesel as a blend with petroleum diesel rather than as a neat fuel. A B20 blend contains 20 percent biodiesel and 80 percent petroleum diesel. A B5 blend contains up to 5 percent biodiesel.

The U.S. Department of Energy’s Alternative Fuels Data Center describes biodiesel as a fuel for compression-ignition engines and distinguishes it from renewable diesel. That distinction matters because both fuels may appear in the same renewable fuel discussion, but they are not identical products. Biodiesel is a mono-alkyl ester produced through transesterification and must meet ASTM D6751 when used as B100 blendstock. Renewable diesel is a hydrocarbon fuel, often made by hydrotreating fats and oils, and meets the ASTM D975 petroleum diesel specification in the United States.

Biodiesel vs renewable diesel

For buyers, the main difference is how the fuel fits existing equipment and operations. Renewable diesel can generally be used as a drop-in replacement or blended at any level with petroleum diesel because it meets the same core U.S. diesel fuel specification. Biodiesel can also perform well, especially in lower blends, but higher blends require more attention to fuel quality, cold weather, storage, and engine approval.

Fuel option	What it means	Typical buying consideration
B5	Up to 5% biodiesel blended with petroleum diesel	Usually the easiest biodiesel blend for existing diesel infrastructure
B20	20% biodiesel and 80% petroleum diesel	Common fleet option that balances renewable content, compatibility, and performance
B100	Pure biodiesel used as blendstock or, in some cases, direct fuel	Requires stronger checks on fuel quality, storage, temperature, and materials
Renewable diesel	Hydrocarbon fuel made from renewable feedstocks	Often simpler for drop-in use, but supply and price may vary by region

Start with the right blend level

The best blend depends on what you operate and where you operate it. B20 is widely discussed because it provides meaningful renewable content while keeping many operating practices close to conventional diesel. The Department of Energy notes that B20 is common because it balances cost, cold-weather performance, and compatibility with conventional engines. It also reports that B20 generally has similar fuel consumption, horsepower, and torque to petroleum diesel, although B20 has about 1 percent to 2 percent less energy per gallon.

B100 and high-level blends are different purchasing decisions. They may support stronger renewable fuel goals, but they can also affect warranties, cold-weather operability, storage life, materials compatibility, and maintenance routines. Because B100 has a solvent effect, it can clean deposits from fuel systems. When a system switches from petroleum diesel to high biodiesel blends, those loosened deposits may initially clog filters. That is not a reason to avoid biodiesel, but it is a reason to plan filter inspections and brief maintenance staff before the first delivery.

• Choose B5 when you want a low-disruption option and have limited control over storage or equipment specifications.
• Consider B20 when you operate a managed fleet, can confirm engine approval, and have a fuel supplier experienced with biodiesel blending.
• Use B100 or high-level blends only after review of engine approval, tank compatibility, cold-weather performance, and fuel handling procedures.
• Compare renewable diesel separately if your main goal is drop-in use with minimal operational change.

Check fuel quality before comparing price

Fuel quality is the first serious buying filter. If a supplier cannot document the applicable ASTM standard, the quote is not complete. B100 biodiesel blendstock should meet ASTM D6751. B6 to B20 blends are covered by ASTM D7467. Petroleum diesel and renewable diesel in the United States are associated with ASTM D975. These standards do not eliminate every purchasing risk, but they provide a baseline for specifications such as sulfur, water and sediment, viscosity, flash point, methanol content, and cold soak filterability.

The Department of Energy’s AFDC also points to the voluntary BQ-9000 program, which combines ASTM fuel standards with a quality management system covering production and distribution practices. Buyers should not assume every supplier is accredited, but BQ-9000 participation can be a useful positive signal when comparing vendors.

Documents to request from a supplier

• A certificate of analysis or fuel quality documentation for the delivered blend.
• The exact biodiesel percentage, not only a generic renewable fuel description.
• Confirmation that B100 blendstock meets ASTM D6751.
• Confirmation that B6 to B20 blends meet ASTM D7467 when applicable.
• Cold-flow properties and any seasonal blending plan for your delivery location.
• Feedstock information if carbon intensity or sustainability reporting is part of your procurement policy.
• Storage and turnover recommendations for the expected delivery volume.

Match biodiesel to engines, warranties, and operating conditions

Before signing a fuel contract, check the engine manufacturer’s position on biodiesel blends. Many diesel engines can use lower biodiesel blends, and many fleets operate successfully with B20, but warranty language matters. The safest approach is to review the vehicle or engine warranty statement, model-year guidance, and maintenance requirements. This is especially important for newer engines with aftertreatment systems and for equipment that may sit idle for long periods.

Cold weather is another major factor. Biodiesel’s low-temperature performance depends on the blend level, the feedstock, and the characteristics of the petroleum diesel used in the blend. The Department of Energy notes that lower biodiesel blends generally perform better in cold temperatures, and that No. 2 diesel and B5 usually perform about the same in cold weather. Fuel providers may use cold-flow improvers or seasonal blending, but buyers should not assume a summer blend is suitable for winter operation.

Cold-weather questions to ask

• What cloud point and cold filter plugging point should we expect for this delivered blend?
• Will the supplier change the base diesel or biodiesel percentage seasonally?
• Is the fuel appropriate for overnight parking, exposed tanks, or remote job sites?
• Do we need tank heating, insulation, or operational changes during winter?
• What is the recommended minimum storage temperature for the blend?

The National Renewable Energy Laboratory’s Biodiesel Handling and Use Guide explains that B100 storage and handling require more attention than B20 and lower blends, especially in cold climates. For buyers in northern states, mountainous areas, or exposed work sites, this can be the difference between a smooth transition and fuel gelling problems.

Review storage, infrastructure, and compliance before delivery

Storage rules are easy to overlook because biodiesel is often discussed as a drop-in diesel option. Lower blends are usually simpler. The Department of Energy’s AFDC states that blends up to B5 are considered petroleum diesel and are approved for existing diesel infrastructure. Blends above B5 may face additional requirements, and buyers should confirm federal, state, and local rules before changing storage practices.

Underground storage tanks need particular attention. AFDC summarizes federal underground storage tank requirements and notes that diesel containing more than 20 percent biodiesel must be stored in compatible systems. Owners and operators storing blends above B20 must be able to demonstrate compatibility for tanks, piping, containment sumps, pumping equipment, release detection equipment, spill equipment, and overfill equipment. AFDC also notes that owners and operators deciding to store biodiesel blends above B20 must notify the implementing agency, usually a state office, 30 days before storage. See also: Charging Equipment.

Even when a rule does not apply directly, the practical lesson is the same: do not order high-level biodiesel before confirming the whole fuel system. Tanks, seals, hoses, gaskets, dispensers, meters, filters, and spill containment equipment all need review. A facility that works well with conventional diesel may still need documentation before storing higher biodiesel blends.

Understand market signals, supply, and policy context

Biodiesel pricing changes with diesel prices, feedstock costs, tax treatment, credit markets, logistics, and local supply. Buyers should compare delivered price, expected energy content, maintenance implications, and reporting value rather than relying only on the invoice price per gallon. B20, for example, has slightly lower energy content than petroleum diesel, so a fair comparison may need to account for fuel economy, route type, idle time, and total operating cost.

Policy also affects availability. Under the federal Renewable Fuel Standard, biomass-based diesel must meet a lifecycle greenhouse gas reduction threshold and can help satisfy advanced biofuel obligations. EPA finalized Renewable Fuel Standard volumes for 2026 and 2027 on March 27, 2026. In that rule, EPA listed total applicable biomass-based diesel volumes of 9.07 billion RINs for 2026 and 9.20 billion RINs for 2027, with one RIN generally representing one ethanol-equivalent gallon of renewable fuel. Buyers do not need to trade RINs to purchase biodiesel, but RFS policy can influence supply, credit values, and producer incentives.

Production capacity is also changing. The U.S. Energy Information Administration’s Biofuels Plant Production Capacity Report, released September 24, 2026, listed 45 U.S. biodiesel plants with 128 thousand barrels per day of capacity as of January 1, 2026. The same report listed 19 plants in renewable diesel fuel and other biofuels with 324 thousand barrels per day of capacity. That does not mean every region has equal access to biodiesel or renewable diesel, but it shows why buyers should compare both fuels where supply is available.

A practical procurement checklist

A structured purchasing process reduces the chance of choosing the wrong blend or working with an unprepared supplier. Use this checklist before requesting bids and again before the first delivery.

Buying step	Why it matters	What to verify
Define the goal	Cost, emissions, compliance, and public reporting may lead to different fuel choices	Blend level, reporting needs, and acceptable operational changes
Check equipment approval	Warranty and engine guidance can limit blend choices	OEM biodiesel position by engine model and year
Confirm fuel standard	Quality problems can damage confidence and equipment	ASTM D6751 for B100 blendstock and ASTM D7467 for B6 to B20
Review storage compatibility	Higher blends may require documented material compatibility	Tanks, lines, seals, pumps, filters, leak detection, and spill equipment
Plan for climate	Cold flow is one of the most common operational risks	Seasonal blend, cloud point, additives, tank exposure, and backup fuel plan
Compare suppliers	Experience matters as much as the quoted price	Delivery history, fuel testing, documentation, emergency support, and references

For a first purchase, consider starting with a controlled trial. Choose a defined set of vehicles or equipment, monitor filters and fuel economy, keep maintenance notes, and compare performance across weather conditions. A measured rollout is especially useful if you operate emergency equipment, agricultural machinery, generators, or vehicles with irregular duty cycles.

Frequently asked questions

Is biodiesel the same as renewable diesel?

No. Biodiesel and renewable diesel can come from similar feedstocks, but they are different fuels. Biodiesel is an ester fuel that must meet ASTM D6751 as B100 blendstock and is blended with petroleum diesel. Renewable diesel is a hydrocarbon fuel that meets the U.S. ASTM D975 diesel specification and is generally treated more like drop-in diesel.

What biodiesel blend should a first-time buyer choose?

Many first-time buyers start with B5 or B20. B5 is the lowest-disruption choice for many existing systems. B20 is common for fleets because it offers a higher renewable share while often maintaining practical compatibility. B100 or high-level blends should be evaluated only after checking engines, storage, climate, and supplier capability.

Does biodiesel reduce fuel economy?

Lower energy content can slightly affect miles per gallon, especially as the biodiesel share rises. The Department of Energy notes that B20 has about 1 percent to 2 percent less energy per gallon than petroleum diesel, although many users report no noticeable performance difference. Actual results depend on duty cycle, engine type, maintenance, and weather.

Can biodiesel be used in cold weather?

Yes, but blend selection and fuel handling matter. Lower blends usually perform better in cold temperatures. Buyers in cold climates should ask suppliers for cold-flow data, seasonal blending plans, additive strategies, and storage recommendations before delivery.

What is the most important supplier question?

Ask for documentation showing the exact blend and the fuel quality standard it meets. A serious supplier should be able to explain ASTM compliance, cold-weather performance, storage recommendations, delivery consistency, and available support if filters plug or fuel quality is questioned.