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Engine Manufacturers Develop Test Specs for B20 Biodiesel

The Engine Manufacturers Association (EMA) has released a test specification for biodiesel fuel to facilitate testing and evaluation of the performance of B20 biodiesel blends in new diesel engines.

The EMA specifications establish technical requirements for blends of petroleum fuel and biodiesel fuel that can be used to assess the effects of such biodiesel fuels on engine performance, durability and emissions.

The Test Specifications for Biodiesel Fuel define a biodiesel-blend fuel with the properties and characteristics that engine manufacturers believe are needed to ensure good performance. Engine manufacturers consider the specifications a critical and necessary first step in further testing and evaluating fuel blends with biodiesel content greater than 5%.

...before the nation moves to increase the biodiesel content of the diesel fuel supply, engine manufacturers and biodiesel producers must fully evaluate biodiesel fuels. The development of a test specification for a blended fuel with 20% biodiesel content is intended to jump-start the testing and evaluation process.

...Considering the tremendous investment that engine manufacturers and the nation have made to develop today's low-emitting and energy efficient diesel technology, we cannot just assume that biodiesel is better. We have to know that a biodiesel blend fuel meets all engine requirements and its use results in equivalent performance and emissions.

—Jed Mandel, EMA President

The EMA Test Specifications for Biodiesel Fuel establish a baseline B20 biodiesel blend that can be used for further testing and evaluation. EMA encourages vehicle owners interested in using biodiesel blends to request that the fuel meet the EMA specifications and that biodiesel fuel providers also produce blends meeting the EMA requirements and BQ 9000 production standards.

The association notes that the EMA specifications are not an approved national fuel standard, and should not be used as such.

The specifications are for biodiesel blends of up to 20% by volume (B20), which are made with biodiesel meeting either ASTM D6751 or EN 14214, and which also meet the following requirements:

EMA Test Specifications for Biodiesel
Item Performance Characteristics Requirements Test Procedure
D1 Blends D2 Blends
1 Flash point, °C, min. 38 52 ASTM D93
2 Water and sediment, vol%, max. 0.05 0.05 ASTM D2709 or D1796
3 Physical Distillation, T90, °C, max 343 343 ASTM D86
4 Kinematic viscosity, cSt@40C 1.3~4.1 1.9~4.1 ASTM D445
5 Ash, mass%, max. 0.01 0.01 ASTM D482
6 Sulfur, wt%, max. Per reg. Per reg.  
7 Copper strip corrosion rating, max. No. 3 No. 3 ASTM D130
8 Cetane number, min. 43 43 ASTM D613
9 Cloud point Equal to or lower than tenth percentile min. ambient temp in geog. area and seasonal timeframe as defined by D975. ASTM D2500
10 Ramsbottom carbon residue on 10% distillation residue, wt%, max. 0.15 0.15 ASTM D524
11 Lubricity, HFRR@60C, micron, max 460 460 ASTM D6079
12 Acid number, mg KOH/g, max. 0.3 0.3 ASTM D664
13 Phosphorous, wt%, max. 0.001 0.001 ASTM D4951
14 Alkali metals (Na+K), ppm, max. Nd Nd EN14108
15 Alkaline metals (Mg+Ca), ppm, max. Nd Nd EN14108
16 Blend fraction, vol. % +/- 2% +/- 2% EN14078
17 Thermo-oxidative stability, insolubles, mg/100mL, max. 10 10 Modified ASTM D2274
16 Oxidation stability, Induction time, hours, min. 6 6 EN14112 (Rancimat)




Great development. I wish they had a B100 spec also.
I thing EMA is mostly a US organization, does anyone know of an Euro ISO test standard for B100?


EMA is a worldwide organization, not just the US makers. I was thinking of the old DEMA...

allen zheng

Ethanol (or a mid-weight alcohol) could be added to rduce NOX and particulates.

allen zheng

Mid-weight alcohol: Propanol, butanol.


Ummm.. B100 already has a spec. Actually 2! ASTM D6751 or EN 14214. The former is the US spec, the latter is the German/European spec.

Rafael Seidl

As of 2004, there is a European industry norm (EN 14214) governing biodiesel composition:



However, this covers only the guaranteed properties of B100, not those of any particular blend. Standardized fuel is a prerequisite for biodiesel certification testing in actual vehicles, which is not yet standard even for new vehicles.

Biodiesel requires greater resilience of the fuel system, especially the eleastomers. Fuel pumps depending on fuel lubricity (unit injectors used by VW, common rail by other manufacturers) can exhibit premature wear. Biodiesel also finds its way into the engine oil during cold starts. Optional passenger compartment heaters for winter operation may not be compatible with biodiesel even if the engine is.

B100 is problematic as it is prone to biological contamination, especially in rarely used vehicles. It may also damage corrosion inhibiting zinc layers in the tank. Small blend fractions of mineral diesel suppress both of these complications.

Car and truck owners should therefore consult their dealer before filling up on biodiesel (blends). This may take some perseverance as the topic is fairly new to many dealers and manufacturers. In some cases, only special versions or vehicles with suitable retrofits are cleared for biodiesel use.

This Wikipedia entry (in German) has detail on biodiesel risks that have not yet made it into the english version:


The bio-diesel pump in my town is 99% bio. Are the properties changed that much with the slight "dilution"?

Rafael Seidl

Ed -

mineral diesel is pretty toxic to microorganisms, so it's quite possible that even a 1% fraction is enough to suppress that problem. Wrt the corriosion issue, I suspect 1% might not be enough, but the blender may also add specific corrosion inhibitors.

In general, this industry needs to walk before it can run. Vehicle manufacturers need time to develop and perform certifications tests and, to gain operational experience wrt to long-term effects. For example, Bosch was unable to clear biodiesel for use in its unit injectors (used in VW diesels) when it became apparent that the fuel caused excessive wear after a number of years (low lubricity).

Similarly, fuel handling and storage could yet throw a curveball, especially in climates that differe substantially from those in Europe where the fuel has a longer track record. For example, microorganisms in some other part of the world might be more resilient against mineral diesel, or mutate into strains that are.

For all of these reasons, a prudent energy policy encourages using biodiesel as an additive initially (e.g. B5 to B20) and ramping up the fraction slowly over time. This should be done broadly to ensure potential problems come to light, but also to achieve the desired environmental and energy security objectives. Besides, if everyone ends up having to chip in (because pure mineral diesel becomes unavailable), no-one gets a free ride. This would do more to increase market share for biofuels than a few ultra-green individuals insisting on B100 (or E100 instead of gasoline) ever will.

The trouble is, US oil companies are unwilling to blend in biodiesel because in the current structure it reduces their bottom line and/or increases their operations risk. Politically, they are too powerful for Congress to force them to do much of anything - quite the reverse may be true.

Eric Nill

Retail (nearly) pure biodiesel is marketed in Oregon as a B99 'blend' for apparently two reasons. Subsidies for biofuels are written in terms of fuel 'additives' hence 99% bio is added to 1% petro diesel. Also for purposes of truth in lableing, a 1% residual of petro is therfore allowed with B99, whereas a B100 label would not allow for even a drop of hydrocarbon based fuel.
Performance characteristics of B99 should equate B100.


Dear Sir,

I am student in Hong Kong, studying chemical engineering.

Can palm oil made bio-diesel meet the EN14214 standard? How about ASTM D6751?

Is that true that ASTM D6751 has no requirement for the cloud point, but EN14214 does?

Best regards,

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