Skip to main content


Please read the information below before using Biodiesel on your tractor.

Kubota User’s Guide to Biodiesel Fuel (BDF) Concentrations up to 20% (B20)

Thank you very much for purchasing a Kubota product. Before using your Kubota product, be sure to read and understand this guide for selecting the correct fuel for your engine. With this guide, B6-B20 Biodiesel fuels (BDF): mixed diesel fuels containing 20% or less biodiesel can be utilized under the following conditions.
Keep this guide with your machine's Operator Manual stored with the machine. Refueling your Kubota product and handling fuel should be done with caution in order to avoid contact with the fuel and spillage that could create a potential environmental or fire hazard. Wear appropriate protective equipment when refueling. This guide gives detailed instructions for using mixed fuels containing Biodiesel concentration of 20% (B20) or less for your Kubota product.

 Applicable biodiesel fuels:

  1. Blended diesel fuels containing 6% thru 20% Biodiesel fuel (B6 - B20) which comply with American Society of Testing Materials ASTM D7467-09a Standard, as revised, can be used for your Kubota equipment without adversely affecting the performance and durability of the engine and fuel system components.
  2. Any mineral oil diesel fuel, if used, must conform to ASTM D975-09b Standard, as revised. B100 fuel used to make Biodiesel blended fuels must meet ASTM D6751-09a Standard, as revised. The final blended fuel B20 must conform to ASTM D7467-09a Standard, as revised. Pure vegetable oil is NOT allowed in any blended fuel.
  3. Allowable blended fuel is mineral oil diesel fuel blended with B100 (i.e. 100% Biodiesel fuel). The blended fuel ratio shall be less than 20% B100 and 80% or more diesel fuel. The B100 source used for Biodiesel blends must be purchased from an accredited BQ-9000 marketer or producer. More information about qualified marketer(s) and producer(s) can be found at .

Preparation of your Kubota product:

  1. Before using Biodiesel fuel concentrations greater than B5, you are advised to replace the oil, oil filter and fuel filter with new oil and filters. For replacement procedures, refer to the Operator's Manual or contact your local Kubota Dealer for the correct parts for your equipment.

Product Warranty, Emission and Other Precautions:

  1. Your Kubota engine emission control system was certified according to current regulations based on the use of non­-biodiesel fuel. When using Biodiesel fuel, the owner is advised to check applicable local and federal emission regulations and comply with all of them.
  2. Biodiesel fuel may cause restricted or clogged fuel filters during cold weather conditions, resulting in the engine not operating properly.
  3. Biodiesel fuel encourages the growth of microorganisms which may cause degradation of the fuel. This in turn may cause fuel line corrosion or reduce fuel filter flow earlier than expected.
  4. Biodiesel fuel inherently absorbs moisture which may cause degradation of the fuel earlier than expected. To avoid this, drain the water separator and fuel filter port often.
  5. Do not use Biodiesel concentrations higher than 20% (i.e. greater than B20). Engine performance and fuel consumption will be affected, and degradation of the fuel system components may occur.
  6. Do not readjust the engine fuel control system as this will violate emission control levels for which the equipment was approved.
  7. Unlike soybean-based and rapeseed-based feedstock, palm oil-based feedstock is less fluid at low temperatures. Consequently, fuel filter performance may be reduced, particularly during cold weather conditions.
  8. The Kubota Warranty, as specified in the Owner's Warranty Information Guide, only covers defects in product materials and workmanship for Kubota approved products. Accordingly, any problems that may arise due to the use of poor quality fuels that fail to meet the above requirements, whether biodiesel or mineral oil based, are not covered by the Kubota Warranty.

Routine handling:

  1. Avoid spilling Biodiesel fuel onto painted surfaces as this may damage the finish. If fuel is spilled immediately wipe clean and flush with soapy water to avoid permanent damage.
  2. When using Biodiesel fuel, you are advised to maintain a full tank of fuel, especially overnight and during short term storage, to reduce condensation within the tank. Be sure to tighten the fuel cap after refueling to prevent moisture build up within the tank. Water in the Biodiesel mixture will damage fuel filters and may damage engine components.

Maintenance Requirements when using Biodiesel fuel B6 thru B20:

  1. Replace the fuel hoses with new Kubota approved hoses at one half (1/2) the suggested replacement intervals as listed in the Operator's Manual. For Example: If the suggested interval is 100 hours to replace fuel hoses, then replace at 50 hours.
  2. Replace the fuel filters with new Kubota approved filters at one half (1/2) the suggested replacement interval as listed in the Operator's Manual.
  3. When using Biodiesel for the first time in your Kubota equipment, replace the engine oil with new Kubota approved oil and filter and follow the service requirements listed in the Operator's Manual.

Long Term Storage:

  1. Biodiesel fuel easily deteriorates due to oxygen, water, heat and foreign substances. Do not store B6 thru B20 longer than one (1) month and B5 longer than three (3) months.
  2. When using B6 thru B20 and storing the machine longer than one (1) month, drain the fuel from the tanks and replace with light mineral oil diesel fuel. Subsequently, run the engine at least thirty (30) minutes to remove all of the Biodiesel from the fuel lines.
  3. When using B5 fuel and storing machine longer than three (3) months, drain the fuel from the tanks and replace with light mineral oil diesel fuel. Subsequently, run the engine at least thirty (30) minutes to remove all of the Biodiesel from the fuel lines.

Listing of Kubota Products Approved for Use with B20 Biodiesel:

Tractor Models
Model Starting Serial # Model Starting Serial # Model Starting Serial # Model Starting Serial #
B2320D 31782 L2800D 85259 L45 50815 M7040F 21073
B2320HSD 55029 L2800F 20326 L4740D 70250 M7040 13245
B26 52920 L3240D 71219 L5040D 70037 M7040SD 68140
B2620HSD 53985 L3240F 40016 L5240D 70297 M8540D 83971
B2630HSD 52815 L3400D 89929 L5740D 70660 M8540DN 83892
B2920HSD 54341 L3400F 20181 M5040D 83365 M8540F 21030
B3030HSD 60031 L3540D 70480 M5040F 21034 M9540D 85231
B3200HSD 55085 L3700 51740 M5640 10360 M9540F 21062
B3300HSD 51378 L3940D 70839 M5640SD 50815 M96S 10014
BX1860 53041 L39-1 60441 M59 51521 M96SD 70152
BX2360 56107 L4240D 70576 M6040D 84103 MX4700D 50850
BX25 56015 L4400D 85869 M6040F 21026 MX4700F 10540
BX2660 57625 L4400F 20002 M7040D 85054 MX5100D 56076
MX5100F 13834
Model Starting Serial #
F2680E 10456
F3080 10595
F3680 14861
ZD221 20503
ZD323-60 31219
ZD326P 31577
ZD326RP-60R 10504
ZD326S 31064
ZD331LP-72 31728
ZD331P-60 30636
ZD331RP-60R 10270
GR2110 15818
Construction Equipment
Model Starting Serial # Model Starting Serial #
K008 21032 R520 20435
KX057 20300 SVL75 10053
KX080 22430 SVL90 10010
KX121 72297 U17 13012
KX41 40449 U25 31014
KX71 12419 U35 40424
KX91 40983 U45 70343
R420 20306 U55 20210
Utility Vehicles
Model Starting Serial #
RTV1100 24791
RTV1140 16326
RTV900 A6727

Kubota Approved Use of B5 Biodiesel Fuels in Kubota Diesel Products

Kubota Tractor Corporation (KTC) announces a global Kubota decision to approve the use of "B5” biodiesel fuels in specified Kubota diesel-powered products. Biodiesel fuels, most often offered in a blended-petroleum format, are derived mostly from vegetable oils, and are offered in the United States as an alternative source for energy.

Biodiesel Fuel (BDF) blended with diesel fuel may be used in the Kubota diesel powered products listed below only if the blended fuel meets the following conditions:

  1. BDF concentration must not exceed 5% by volume (B5 blend). Greater concentrations increase the likelihood of corrosion and failure of the aluminum, zinc, rubber, and plastic parts of the fuel system.
  2. The petroleum diesel fuel base must meet the American Society for Testing and Materials (ASTM) D975 fuel specification (or the European EN590 specification). The pure biodiesel base must meet minimum requirements provided by ASTM D6751 (or EN14214) prior to blending. Raw pressed vegetable oils are NOT acceptable for use in any concentration.
  3. Kubota strongly recommends that B5 blend be purchased from a BQ-9000 accredited producer or certified marketer. Kubota discourages local blending of BDF, because it is difficult to meet the quality requirements explained above.
  4. Users of Kubota Emission Certified Engines are responsible for obtaining any required local, state or national regulatory approvals for the use of BDF.

Enhanced engine care may be required even if the fuel meets the above standards. Kubota has the following concerns and recommendations regarding the use of B5 blend:

  1. B5 blend attracts moisture and may contain higher water content than conventional diesel fuels. Keep storage and vehicle tanks as full as possible and ensure all caps and covers are installed properly to prevent water from entering and collecting in the fuel system.
  2. Follow the oil change intervals recommended by Kubota in your operator's manual. Extended oil change intervals may result in premature wear or engine damage.
  3. B5 blend is biodegradable and degradation of the fuel supply is accelerated by the presence of water, heat, oxygen and other impurities.
    • To avoid damage caused by fuel degradation, B5 blend should not be used if it has been stored for more than 3 months.
    • If an engine is going to be placed in storage, the B5 blend should be flushed out by operating the engine for at least 30 minutes on conventional diesel fuel.
  4. In consideration of the particular properties of BDF it is very important to follow the maintenance interval and procedures regarding the fuel system as specified in the operator's manual.
    • Microbial contamination and growth may cause corrosion in the fuel system and frequent plugging of the fuel filter.
    • Cold weather conditions can lead to fuel system plugging, hard starting or other problems
    • BDF attracts moisture and may contain higher water content than conventional diesel fuels.
  5. B5 blend will damage painted surfaces. Clean up spills immediately.
  6. Tampering with the factory adjustments on fuel system components is a violation of EPA regulations, and can result in denial of warranty coverage.

Kubota's statement of allowance to use B5 blend in no way changes the published warranty terms and conditions. Fuel system failures that can be attributed to the quality of fuel used are ineligible for warranty coverage. Please see your local Kubota dealer for more information.

Listing of Kubota Products Approved for Use with B5 Biodiesel:

Tractor Models
B21 BX1830 L3240 L4630 M110 M8200
B26 BX1850 L3400 L4740 M120 M8540
B2630 BX22 L3430 L48 M125X M9000
B3030 BX2200 L3540 L5030 M4800SU M9540
B7410 BX2230 L3830 L5240 M4900 M95S
B7510 BX23 L39 L5740 M5040 M96S
B7610 BX2350 L3940 M105S M5700 MX5000
B7800 BX24 L4240 M105X M6040
BX1500 L2800 L4330 M108S M6800
BX1800 L3130 L4400 M108X M7040
Mower Models
F2260 ZD18
F2560 ZD21
F2880 ZD25
F3060 ZD28
F3680 ZD321
G2160 ZD326
GF1800 ZD331
Construction Equipment
K008-3 R420S
KX080-3 R520S
KX121-3S U15
KX161-3S U25S
KX41-3 U35S
KX71-3 U45S
Utility Vehicles
RTV1100 RTV900