Tan_Hands - different states have different rules regarding fuel tax on bio-diesel. Here in NC, the legislature passed a law last year exempting the first few thousand gallons of fuel from tax, if it's made for personal use by the end user.

Re how long it takes to recoup the 7K investment, for my wife and I (6.0 Excursion and 6.4 F450, plus farm equipment) the ROI is less than a year (more on this below).

Goneon - good summary and good points. To elaborate on your points,

Yes - gelling is an issue in colder weather. For spring, summer and fall usage in most of the US it's a non-issue though.

Re the deposits, bio-diesel is a good solvent, and when you switch your vehicle over to it for the first several thousand miles you will need to change your fuel filters more often. Over time, regular diesel will leave a film residue inside the fuel lines and tank, and biodiesel will disolve this and leave it in the filter.

Re the seals, inside the engine should be a non issue, unless you experience some type of fuel system leak that contaminates the oil. Re the seals in the fuel system, pretty much all injection systems manufactured post 2002 utilize viton seals, which are suitable for use with bio diesel (such as 6.4 PSD's and 6.0's too). Many injection pumps that are older than 2002 will require upgrading to viton seals for continued BD use.

BD is not for everybody, and many early brewers produced a poor quality product that have resulted in some bad experiences. There are no issues that I am aware of regarding the high pressure injection systems and BD (not to say that they don't exist - just that I'm not aware of them).

As far as "pennies per gallon", I can brew my own BD for a little over a buck a gallon. Locally, diesel sells for 4.79 right now, so that's a big delta. In my instance, for every ten thousand miles of operation with bio diesel versus dino diesel, I save approximately thirty-four hundred dollars.

Between my wife's Excursion and my F450, we usually average around 45,000 miles per year combined. At 4.79 a gallon and 10mpg average on the F450 and 15mpg average on the Excursion, we're slated to spend over seventeen grand on fuel this year.

For the same amount of miles driven on our own BD, and accounting for 1mpg worse mileage on BD, we'd spend five grand in fuel.

A twelve thousand dollar annual savings - for us - makes it worthwhile to pursue manufacturing high quality bio diesel.

 

So...If anyone IS going to run bio-diesel in higher concentrations, given that is indeed a solvent that will "clean" the fuel system from dino diesel deposits, then it seems prudent to change the filters WHEN you convert to 100% bio to keep the stuff from the old filters out of the new system? Seems pretty straight forward, but it does seem indicitive of some of the fore thought to be done before the change over.

OBTW: Why isn't this "solvent" action an issue with the 5% Ford recommends? Doesn't the solvent action take place at that %age?

 

This is Internationals official stance on Bio blends.;

"Biodiesel Blends (up to B5)

Currently, all blends up to B5 have characteristics that are indistinguishable from diesel fuel. Work is underway to include specifications for blends up to B5 in the ASTM D975 standard. Navistar approves of blends up to B5, provided that the two components satisfy current specifications ASTM D6751 and ASTM D975. Quality biodiesel blends up to B5 should not cause engine or fuel system problems.

Biodiesel Blends (B6-B20)


Biodiesel blends B6-B20 have different characteristics than diesel fuel. B20 is used by fleets in the United States, because B20 balances performance, emission levels, cost, and availability. B20 is also the minimum blend level that qualifies as an alternative fuel, in compliance with the Energy Policy act of 1992. Blends lower than B20 are used regionally, depending on favorable tax incentives that vary from state to state.

There is no ASTM standard for B6-B20 blends, which makes it difficult for consumers to determine fuel quality. The ASTM is working on a standard for B6-B20 blends; in the interim, the EMA released a B20 Test Fuel Specification (June 2006) defining characteristics for fuel quality and consistency. Until the ASTM B6-20 standard is issued, the EMA B20 Test Fuel Specification is recommended for users requesting quality and consistency of B20 blends.

The National Biodiesel Board (NBB) has established a voluntary biodiesel BQ9000 Quality Management Program to train, certify, and accredit biodiesel producers and sellers. This program should significantly promote product quality and consistency in the emerging biodiesel industry. See www.nbb.org, for more information.

If customers want to use B6-B20 biodiesel blends, Navistar recommends the following:


Biodiesel blends should meet the EMA B20 Test Fuel Specification.
Biodiesel blends should be procured from a BQ9000 accredited producer or distributor.
The customer should follow Navistar's recommendations for biodiesel blends"