the last time I filled the tank at MUSA I noticed the they had a sticker that said that their fuel now has 5%-20% of biodiesel in it. I noticed a significant drop in mpg on that tank full, about 1.5 miles per gallon less then. previous.
Anyone else notice a drop in millage when using that Biodiesel mix.

 

Well known that most will loose some mpg's.

Less energy in the fuel.

 

It's just announcing "We are giving you less of what you are paying for. Thanks for the extra cash."

 

well I had no idea. Never knowingly put that Biocrap in my tank before.
No more diesel from Murphy's USA

 

Pretty much any fuel you get is going to have biodiesel in it. Every pump I've stopped at for the last 5 years has had some sort of blend sticker on it.

 

Yep, I don't think brand has much to do with it. State laws vary quite a bit, and lots of states require bio regardless of who sells it.

 

I am fortunate here. Maryland does not require it yet.

I fill up at the local co-op and get 50 cetane diesel.

 

I'd run a few more tanks of the blend before I condemned it. I think your math is off. Because of the way diesel fuel foams when refueling, it is virtually impossible to accurately measure fuel economy on a single fuel event.

We used to remove the tank, weigh it, add a know quantity (weight) of fuel, run a test cycle, remove the (now near empty) tank, and reweigh the tank.

The process would be repeated until a statistically valid result could be attained.

The heating values (btu content) of the bio is very similar to straight Diesel (can't remember the exact difference, as it's been a number of years since I worked on this stuff).

The biggest thing from the research we did in 2006-2009 is that the biodiesel reduces DPF soot loading slightly and increases passive regeneration that occurs in normal driving , resulting in fewer active / forced regen events.

The Biodiesel also has better lubricity than straight diesel, so that would be a positive for fuel system life.

Negatives are poorer low temperature characteristics (higher cloud point) and a tendency to scrub deposits from dirty fuel systems resulting in poor filter life (if you have dirty tanks). Storage stability is also an issue.

Some states mandate a percentage of bio for all road fuel, and have changed the laws so it doesn't have to be disclosed on the pump. Illinois is like this, and I assume they aren't alone.

 

Actually bio diesel produces more soot due to the lower BTU's, therefore you regen more.

 

No, that's not true in any of the studies I did, either dyno testing or on-road, or any other controlled engineering studies I am familiar with.

Our data was quite repeatable.

The thought is that the higher oxygen content of the bio leads to improved passive regeneration, so you end up with lower soot accumulation rates and ultimately fewer active regeneration.

A lower BTU content wouldn't lead to more soot formation, either. 1D fuel has lower BTU content than 2D fuel, but was often specified in fleets as a way to reduce exhaust smoke (soot).

Can you cite a source?

 

My right foot and 8 years worth of DPF's.

First generation of the DPF with the 6.4 and now with the 6.7.

About 200K miles worth.

 

Very interesting finn, didn't know all of that. I've heard mixed things for those running bio blends.

Why do engine manufacturers require mostly conventional diesel in bio blends? I've never heard of an engine that's factory spec'd to run anything higher than B20. What's wrong with B100?

 

Not a Ford response but a works for a refinery response.

In short, your truck was not designed to meet emissions with E100. Just like E10 for gas is the norm in much of the country it is becuase the regulators decided it could not make a material impact on the emissions on vehicle designed and tested on E0 fuels.

Long answer is much more complex. Prior to modern emissions equipment requirements, some semi-modern diesel did just fine on E100 while others had fuel pump seal issues but all these could be somewhat or completely solved with modern "rubber" compounds. This all a significant oversimplification of all the issues on both sides but in the end, Biodiesel in itself is not evil but it is a risk (and not really an ecological benefit at this point).

 

I've been retired for a while, and pretty busy with other things, so I haven't kept up with the fuel stuff, but when I was involved, the biodiesel thing was just taking off and the Diesel industry was tied up implementing aftetreatment, so there just weren't the engineering resources available to spend a lot of time or money qualifying a fuel that was really a niche market. The blends were close enough to straight Diesel that they are considered to be interchangeable.

The fledgling bio industry was made up of either small players, relative to the major oil companies, or large players with no diesel engine expertise, and the product was splintered, with everything from chicken renderings to rapeseed to corn oil base stock, all with slightly different final product characteristics and limited product quality specifications.

Also, cold performance was a problem with higher blend ratios.

 

Free anecdotal information is worth what you pay for it.

Sorry.