General information only, last reviewed October 25, 2026. Full notice and dates to watch at the end of the page. A date on this page has passed. Check the current rule at the source before you rely on it. Dates to watch
Renewable diesel and biodiesel get used as if they were the same thing, but they are two distinct fuels. They start from similar feedstocks, then go through different processes and behave differently in the tank and the cold. For a jobber deciding whether to carry them, the differences are worth knowing.
The core difference
Both can come from vegetable oils, animal fats, and used cooking oil, but the processing splits them. Biodiesel is made by transesterification into fatty acid methyl esters (FAME), and it is usually blended with petroleum diesel. Renewable diesel is made by hydrotreating into pure hydrocarbons, chemically much like petroleum diesel, so it can run as a drop-in fuel on its own.
Reading the blend numbers
Biodiesel blends use a B number for the percentage of biodiesel:
- B5 (5%) generally meets the standard diesel spec, ASTM D975.
- B6 to B20 fall under ASTM D7467; B20 is common in fleets.
- B100 (pure biodiesel) must meet ASTM D6751 before blending.
Renewable diesel uses an R number the same way, so R99 is 99% renewable diesel and R100 is pure. R99 became the standard product, and the reason is tax law. The federal blender's tax credit paid $1.00 per gallon and required a trace of petroleum diesel in the mix, as little as 0.1%, so producers blended to 99% to capture it. That credit ended with 2024. Its replacement, a producer-side credit (Section 45Z) for fuel sold from 2025 through 2029, does not require any petroleum in the mix.
The cold-weather story
Cold weather is where the two fuels split. Biodiesel, especially B100, gels at higher temperatures, roughly 30 to 40°F depending on feedstock, so it needs cold-weather care. Renewable diesel handles cold as well as petroleum diesel or better. Producers can tune its cold-flow during manufacturing, and arctic grades are rated to roughly -40°F, which makes it the easier of the two in cold climates.
What it means for a jobber
These are more products to source, blend, store, price, and track, each with its own spec and blend level. Renewable diesel handles like regular diesel; biodiesel blends add blending and cold-weather considerations. Carrying them well means treating them as tracked products, right alongside your DEF and conventional fuel. It is one more way the product mix keeps expanding.
Where FastDragon fits
FastDragon Fuel Jobber tracks renewable diesel and biodiesel blends as distinct products with their own cost, pricing, and tax treatment, so adding a low-carbon line does not muddy your numbers.
Questions we hear a lot
Can renewable diesel run in existing diesel engines and tanks?
Yes. It meets the same ASTM D975 spec as petroleum diesel, so existing engines, dispensers, and storage tanks take it without modification. Fleets often make the switch with no change beyond the fuel order.
Does biodiesel need different storage and handling?
It needs more attention than petroleum diesel. Biodiesel attracts water and oxidizes over time, so tanks must stay clean and dry, and long storage usually calls for stability additives. Higher blends can also soften older gaskets and hoses, which is worth checking before carrying B20 and up.
Which states drive renewable diesel demand?
California, Oregon, and Washington, through their low-carbon fuel programs. California's LCFS pays credits for low-carbon fuels, which is why the bulk of U.S. renewable diesel is sold there and why West Coast jobbers see it far more often than the rest of the country.
Do renewable diesel and biodiesel generate RINs?
Yes, both can qualify as biomass-based diesel under the Renewable Fuel Standard. EPA rules set RIN generation at 1.5 RINs per gallon for biodiesel and 1.7 for renewable diesel through 2026. Starting January 1, 2027, the renewable diesel value drops to 1.5, or 1.6 for producers who show EPA a higher energy or renewable content.EPA rules set RIN generation at 1.5 RINs per gallon for biodiesel and, since January 1, 2027, 1.5 for renewable diesel, or 1.6 for producers who show EPA a higher energy or renewable content (renewable diesel earned 1.7 through 2026). Those credits are a big part of the economics that bring these fuels to the rack.
Sources: DOE on renewable diesel and biodiesel blends; the diesel and biodiesel specs in the NIST Handbook 130 (2026) fuels regulation; IRS Notice 2005-62 and Notice 2007-37 (the 0.1% diesel rule), Form 8864 instructions (credit end date), and the Section 45Z credit page; RFS rules in 40 CFR 80.2 and 80.1415, and EPA's 2026 RFS rule (91 FR 16388).