Biodiesel Report - B20 and Your Car's Warranty

IIRC, the reason VW recommended 5% max on biodiesel was because of the particulate filter clogging up.

 

They, and others, took the justifiable cheap approach.
DPFs require a regen cycles in which fuel is sprayed onto the filter to reduce the caught soot to finer ash. The simple, cost effective method is to just inject some fuel into the cylinder on the exhaust stroke. Because of physical differences between the fuels, not all the biodiesel gets swept out of the cylinder under this method. Above 5%, the left behind BD can cause problems; gumming up valves or getting into the crankcase oil.

For concentrations above B5, the fuel needs to be injected directly into the exhaust for the regen cycles.

The issue here is that car manufacturers built for the federal standards, but states are pushing for standards exceeding the federal. We need a more unified collection standards. Like with emission standards. Or we'll end up with these problems, and the manufacturers' cost will rise to meet the varying ones, or they'll ignore the smaller markets.

 

...lots of new info, this is interesting article per Trollbait really throws a monkey wrench if the states go off in different directions. My understanding (which is challenged by this article) was that normal diesel pumps had 100% dino-diesel but you could go to a B20 biodiesel pump at some stations. The article says my own state Virginia mandates 2% bio (B02) in diesel; this is news to me and not clear if they are talking about all pumps or just state vehicles require this. EU has more experience and stays around B5 I think so US state-mandated B>5 is asking for trouble I would think.

 

There are a small number of B20+ biodiesel stations. Any diesel that is not B0 needs to be labeled at the pump, just as the E10 pumps are labeled - this may contain up to 10% ethanol
Alternative Fuels Data Center: Biodiesel Fueling Station Locations

It is state owned vehicles that the mandate is for, public diesel stations do not need to comply. B0-B5 is needed for the newer particulate filters in some cars.

 

Mandated Bx might've saved my TDI from HPFP destruction, since the USA's ULSD scar score is so high compared to the rest of the civilized world.

 

I don't understand. What in B5 would have helped your fuel pump? Are there more failures in the US than Europe.

 

That's my point. The relatively abrasiveness of USA ULSD is part of the reason why more HPFP's fail in the USA than anywhere else. Bosch didn't redesign the HPFP for our market, and VW took their chances on it failing. BioDiesel has very low scar score because it has great lubricity. It helps tremendously in keeping the HPFP from self-destructing. You only need a concentration of 2% to make the scar score low enough to not be a bother anymore, even with most of the ULSD pumps out there that have a worse-than-legal scar score.

 

There was a study conducted several years ago comparing the lubricity of additives to ULSD, including biodiesel (B2). According to that study, B2 was far more effective in increasing lubricity than any other additive...

Lubricity Additive Study Results - Diesel Place : Chevrolet and GMC Diesel Truck Forums

 

That seems like a no brainier policy then to ask for B2. Even if we are talking crazy expensive botique algea based bio at $10/gallon all you need to do is add a new $0.15/gallon tax unless it is at least B2 and the industry will quickly move not to pay the tax. If it makes vehicles less expensive to maintain its all to the better.

 

Hey wxman, didin't one or two hpfp failures pop up on Fred's TDI where the users were using bioduesel?

 

this brings up the question, why did USA go for B20 for small users, versus B02 for all diesel?
I do not have the background. But "no brainer" is a bit strong. If we went B2 it would probably be soybean oil FAME.
That may have cold flow issues and other spec issues, that could probably be coped with some care.

I don't know if wxman's lubrication theory is universally accepted, but the reason B02 might be effective is you are at 20000 ppm dose versus say much smaller ppms of other additives.

 

Alternative Fuels Data Center: Biodiesel Blends

But in 1992 they didn't really know about the new particulate filters that have been designed for B5 or lower.

It seems pretty straightforward to tax B0 higher than B2 and get both more biodiesel and help lubricate the high pressure fuel pumps. I would think they would make the hpfp work with B0 though. I don't know what the technical issues are.

 

Of course, either soy or canola biodiesel would be much cheaper and both already have the added bonus of an EROI corn ethanol can only dream of.

 

Here's a more formal study of lubricity of biodiesel blends...

http://www.eng.wayne.edu/user_files/414/file/Quick_Upload/Lubricity_%20Kapila%281%29.pdf

Appears to have essentially the same conclusion...lubricity increases dramatically @ B2.

 

The other additives may be poor fuels, though. Isn't one of the claims for top tier gasoline that it contains more effective additives that meant less were needed, and thus more actual gasoline was in the gallon you bought. An additive for either fuel that doesn't burn as well as the fuel has the risk of building up deposits in the engine if the concentration is too high. Biodiesel is a fuel in its in own right with a btu content not much less than diesel. Being a good lubricant for the fuel pump is a side benefit.

I'd say it's more the manufacturers not taking the full consideration of what the tax benefits for B20 meant to the US diesel supply. The B20 F250+, likely the GMs, have particle filters. Most of the others opted to take the less expensive route of not putting a dedicated exhaust fuel injector in for regen cycles in. They didn't think their cars would see above B5 in the US, or simply felt that diesel sales weren't large enough to worry over lost ones in areas with blends higher than the 5%.

 

I was talking about the european diesels, that are designed for that market and brought over here. There aren't really technical challenges, only cost consideration.

If the goal is to get to 2% or 3% biodiesel then taxing diesel with lower content more would be very effective. Currently tax policy from 1992 tries to get 20% in a small percentage of vehicles. I do not know all the issues, but it sounds like given current imported diesels the US may want to update its biodiesel policy.

Note we had a big spike in biodiesel that was exported to europe, until they put a tarrif on it. 2012 should be the highest level ever. I do not know where biodiesel production means soybean prices in the US go up. That is why I mentioned algea, which if we are going for 5% seems the best viable method for say 2020. Even if algea based biodiesel cost 3x more than oil based diesel, at 2% it will only raise the price 4%. By the time we want 5%, it should only be twice as expensive, so that would raise the price 5%. A 5% tax on diesel less than B2, would easily move oil companies to incorporate the change. Soy and palm oil based grease may even make it go up less. The beauty of the tax is you do not need the mandate. If pure dino-diesel is better, which it appears not to be, then companies can simply pay the tax. Oil companies currently pay a tax for not putting in the mandated cellulistic ethanol, but here economics are different.

 

Yes. Using Bio helps band-aid the situation, but it doesn't fix the poorly designed HPFP. Why VW/Bosch couldn't simply rip-off and scale down a design from any domestic [Ram Cummins, Ford, GM] truck is beyond comprehension. Chalk it up to German stubbornness.

 

The pump in the Jetta and Golf is a Bosch CP4.1, which is in fact from the same family as the CP4.2 used by Ford and GM. The CP4.2 is a dual piston design for larger V engines while the CP4.1 is a single piston for smaller engines. So it is actually a scaled down design from a domestic truck. Or the 4.2 may be a scaled up version of the smaller pump, I'm not sure which one came first.

 

Make sure your diesel is able to run B20 (owners manual). Also if you will be running B20 versus straight diesel, keep extra fuel filters on hand. B20 Is an excellant fuel system cleaner, will plug up your fuel filters a couple on times.

I know this from experience,

DBCassidy