The D93 Flash Point method reports the temperature at which ignitable vapors are produced and is a requirement for safe fuel storage and handling. This method can also be an indirect measure of fuel contamination, i.e. gasoline in diesel.

The D97 Pour Point method determines approximately the lowest temperature at which a fuel can be pumped. This test is appropriate for materials with freezing points above -52°C

The D130 Copper Strip Corrosion method determines the corrosiveness of the fuel to copper metal and is a general indication of the tendency to cause corrosion of metal surfaces.

The D445 Kinematic Viscosity method determines the viscosity of the fuel. Fuel that is too low or too high in viscosity will not inject or atomize properly in the cylinder. This can affect fuel economy and possibly cause excessive engine wear over time.

Cetane is a measure of ignition quality for diesel fuels. Higher cetane fuels tend to increase power output and engine efficiency, start easier (especially in colder temperatures), and reduce exhaust smoke and odor. The cetane test is appropriate for diesel, biodiesel, and diesel/biodiesel blends. The D2699 and D2700 RON/MON Octane determination is the appropriate ignition quality test for gasoline-based fuels. This test is performed by an outside laboratory.

The D664 Total Acid Number method measures the amount of free fatty acids and mineral acids in biodiesel and diesel blends (B6 to B20). Excessive acid values can lead to engine deposits and corrosion.

The D874 Sulfated Ash method determines the non-combustible material in a fuel such as metallic deposits. Significant ash content can cause engine deposits and excessive engine wear. The D874 method is more sensitive to ash formation from sodium and potassium and is therefore more appropriate for biodiesel; the D482 Ash method is appropriate for diesel and diesel blends (B6 to B20).

The D1160 Vacuum Distillation method is suitable for giving the boiling point range of biodiesel. Biodiesel has a very narrow boiling point range, and this method assures that no high boiling adulterants such as unprocessed fats or oils are present. The D86 method is more appropriate for diesel and diesel blends.

The D2500 Cloud Point method determines the temperature at which fuel particles begin to visibly form a cloud of crystalline fuel molecules, but fuel flow is not yet completely restricted. For diesel and diesel blends, the Cloud Point gives an indication of where the Cold Filter Plug Point (D6371) may be, which is typically only a few degrees lower than the Cloud Point. At the Plug Point temperature, fuel flow is restricted. This test is suitable for biodiesel, diesel, and diesel blends.

The D2709 Water & Sediment method is used to measure the amount of visible water, sediment, and suspended matter in fuel oils such as diesel and biodiesel. The D1796 Water & Sediment method is more appropriate for heavier petroleum products like oil. These methods do not detect entrained water; the D6304 Karl Fischer moisture titration is more suitable for entrained water.

The D4052 Density method measures the density of liquids. Standard density measurements are generally taken at 15.6°C and several measures of density can be obtained. Density is the mass per unit volume of fuel and is typically reported as g/mL. Relative Density and Specific Gravity are the same measurement and is the density of the fuel divided by the density of water at the same temperature. This value is unitless. API gravity is a calculated measure of density where low API indicates a high-density fuel and high API indicates a low-density fuel.

The D4052 Density method measures the density of liquids. Standard density measurements are generally taken at 15.6°C and several measures of density can be obtained. Density is the mass per unit volume of fuel and is typically reported as g/mL. Relative Density and Specific Gravity are the same measurement and is the density of the fuel divided by the density of water at the same temperature. This value is unitless. API gravity is a calculated measure of density where low API indicates a high-density fuel and high API indicates a low-density fuel.

The D4176 Visual Inspection provides a visual assessment of fuel quality. Procedure 1 looks for visual evidence of haze, water droplets, and/or sediment. Procedure 2 uses a numerical description for the strength of haze present in the fuel.

The D4530 Carbon Residue method measures the amount of carbonaceous material after evaporation and pyrolysis of the sample. This will give a relative indication of coke-forming ability. This method is more commonly used with biodiesel samples.

The D5453 Sulfur method measures the total sulfur content by UV fluorescence. This test is suitable for most liquid hydrocarbons and some solids (i.e. fats and feedstock materials) if they can be dissolved in toluene. This method is not suitable for glycerin.

The D6371 Cold Filter Plug Point method measures the temperature at which the fuel has produced enough crystalline structure (freezing) to restrict flow. This test is suitable for biodiesel, diesel, and diesel blends.

The D6584 Free and Total Glycerin method for biodiesel measures the amount of free glycerin (glycerin by itself) and glycerides (glycerin attached to fatty acid chains- mono-, di- and triglycerides). The method will report a Total Glycerin value which is the combined amount of free glycerin plus the amount of glycerin bound by fatty acid chains. These compounds are residual contaminants of the biodiesel production process.

The D7321 Total Contamination method uses filtration to measure the total contamination by mass in biodiesel. The D6217 Total Particulates method is more suitable for diesel and diesel blends. These filtration methods are typically not suitable for gasoline and gasoline blends; the D381 Gum Content is a better method for these fuels.

The D7501 Cold Soak Filtration method gives an approximation for the cold weather performance of a B100 product. The sample is chilled, warmed back to room temperature, and then timed for how long it takes to pass through a filter. The test is designed to check for particulates that may come out of solution at colder temperatures. The test is designed for B100, although the test can be performed for diesel and diesel blends.

The D6304 Coulometric KF Moisture method measures the level of moisture entrained in a fuel sample by Karl Fischer titration. This test is very sensitive and can detect water in the low ppm (parts per million) range. For ethanol and ethanol blends, or samples expected to contain higher amounts of water, the E203 Volumetric KF Moisture method is more appropriate.

The EN 14103 FAME method is used to determine the mass percent of methyl esters in a B100 product. This test should not be confused with the D7371 Biodiesel Content method that measures the amount of biodiesel (FAME) in a diesel blend.

The EN 14110 Methanol Content method determines the amount of residual methanol in biodiesel.

The EN 14538 Metals analysis uses ICP-OES to measure calcium, magnesium, sodium and potassium in biodiesel. This analysis is offered as a package and includes D4951 Phosphorus. This test is intended for biodiesel, but any hydrocarbon fat or oil can be analyzed as long as it can be dissolved in kerosene. Other elements can be assayed as well- check for availability.

The EN 15751 Oxidation Stability method gives a relative measure of fuel stability. The test is commonly used for B100 products but is valid for diesel blends containing at least 2 % biodiesel.

Mass Spectrometry (GC/MS) can be used to identify unknown compounds or to give a more detailed look at the composition of a fuel product or feedstock material. This instrument has been especially useful for analyzing filter residue from plugged filters or analyzing fuel samples that may have been adulterated (vandalized).