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Fuel Regulations

Japan: Fuels: Diesel Fuel

Background

There are two quality standards for diesel fuels in Japan: a mandatory standard specified in the “Law on the Quality Control of Gasoline and Other Fuels” (“Quality Assurance Law”) and a voluntary Japanese Industrial Standard (JIS) K 2204 “Diesel Fuel” [6791][6792].

The Quality Assurance Law provides mandatory requirements for sulfur, cetane index and T90 distillation temperature that diesel fuel must meet. It also includes for reference purposes, a standard diesel fuel specification for viscosity and low temperature operability requirements.

To accommodate biodiesel fuel blends, the Quality Assurance Law has been amended as outlined in the discussion on Japanese biodiesel standards. The amendments, effective March 2007, include limits on the amount of FAME and triglycerides in diesel fuel to distinguish it from a biodiesel/diesel fuel blend and to prevent the use of unprocessed vegetable oils.

Diesel Market Fuel

Fuel grades and specifications as per JIS K 2204 and the Quality Assurance Law are given in Table 1. The required low temperature operability depends on time of year and the geographical area. Therefore, both the “standard diesel fuel” of the Quality Assurance Law and JIS K 2204 recommend a grade of diesel fuel with a maximum low temperature operability limit that should be used for each month of the year in each district in Japan. The low temperature operability properties—cold filter plugging point (CFPP) and pour point—are summarized in Table 2. The low temperature operability properties for the “standard diesel fuel” of the Quality Assurance Law coincide with the values in JIS K 2204 and therefore, the grade numbers of JIS K 2204 are used in Table 2 for convenience.

The low temperature operability requirements in the “standard diesel fuel” of the Quality Assurance Law are based on “typical” climatic conditions. Those for JIS K 2204 are more conservative and are based on extreme low temperatures experienced in the past few decades. Table 1 also lists the minimum expected monthly temperature and the corresponding grade that should be used.

Table 1
Japanese diesel fuel (and B5) specifications
Fuel Property Unit Quality Assurance Law JIS K2204:2023 Test
1S 1 2 3 3S
Cetane Index1, min   45 50 50 50 45 45 JIS K2280
Sulfur, max % mass 0.001 0.001 0.001 0.001 0.001 0.001 JIS K2541 -1, -2, -6, -47
Distillation, 90% v/v rec., max °C 360 360 360 350 3302 330 JIS K2254
FAME, max % mass 0.13            
Triglycerides, max % mass 0.01            
Viscosity @30°C, min mm2/s 1.7 2.7 2.7 2.5 2.0 1.7 JIS K2283
Flash Point4, min °C 45 50 50 50 45 45 JIS K2265
Pour Point, max °C Table 2 +5 -2.5 -7.5 -20 -30 JIS K2269
CFPP, max °C Table 2 - -1 -5 -12 -19 JIS K2288
Carbon Residue5, max % mass 0.1 0.1 0.1 0.1 0.1 0.1 JIS K2270
Density @15°C, max     0.86 0.86 0.86 0.86 0.86 JIS K2249
Lowest expected monthly temperature °C   5 & above 0 & -5 -10 -15 & -20 -25 & -30  
1 Cetane number may also be used
2 350°C and below when kinematic viscosity (30°C) is 4.7 mm2/s and below
3 FAME >0.1 to ≤5% is allowed if the blend meets additional requirements
4 Pensky-Martens method
5 CCR, from 10% distillation residue

Low temperature operability requirements for Japanese diesel fuel are shown in Table 2. For each month, the grade on the left is that recommended by the Quality Assurance Law and the grade on the right is from JIS K 2204:2004.

Table 2
Low temperature operability requirements
DistrictJanFebMarAprMayJunJulAugSepOctNovDec
Hokkaido (except Donan)33S33S23S12111S11S1S1S1S1S1112233
Donan area in Hokkaido33332312111S11S1S1S1S1S1112233
Touhoku2323231S21S11S1S1S1S1S1S1S1S1S11S122
Chubu23231S31S21S11S11S1S1S1S1S1S1S11S21S3
Kanto22221S21S11S11S1S1S1S1S1S1S1S1S11S122
Hokuriku22221S21S11S11S1S1S1S1S1S1S1S1S11S11S1
Tokai22221S21S11S11S1S1S1S1S1S1S1S1S11S11S1
Kinki22221S21S11S11S1S1S1S1S1S1S1S1S11S122
San-in22221S21S11S11S1S1S1S1S1S1S1S1S11S11S1
San-yo22221S11S11S11S1S1S1S1S1S1S1S1S11S11S2
Shikoku11221S11S11S1S1S1S1S1S1S1S1S1S1S1S1S11S1
Kyushu22221S11S11S1S1S1S1S1S1S1S1S1S1S1S1S11S1
Okinawa1S1S1S1S1S1S1S1S1S1S1S1S1S1S1S1S1S1S1S1S1S1S1S1S

Certification Fuel

The following table lists diesel fuel specifications for emission testing over the 10-15 mode procedure. The properties of certification fuel correspond to the JIS No. 2 diesel, with sulfur content gradually lowered, as low sulfur fuels become available on the road.

Table 3
Certification fuel specifications (10-15 Mode)
Fuel Property Unit Limit Test
Min Max
Cetane Number   45 - JIS K 2280
Sulfur % mass - 0.2 JIS K 2541
Viscosity @40°C mm2/s 2.5 - JIS K 2283
Flash Point °C 50 - JIS K 2265
Distillation, 90% v/v rec. °C - 350 JIS K 2254