quote:

I ask if this were such a big issue why wouldn't more engines have oxidization related problem as all diesel vehicles have fuel returned to the tank in similar conditions? I believe some / many motor manufacturers actually rely on the fuel flowing thru the fuel system & injectors to carry out a portion of the engine cooling. Therefore one would presume the return fuel likely carries quite a bit of heat.
PD

From all the Bosch related research data I could find when considering this model, fuel oxidation and high PH were the primary LAB tested concerns. Besides the old well known Biodiesel issues like poor conversion or contaminates from under-filtered fuel. Real world common rail results are actually much better IMO.

Other manufacture designs like my 6.0L powerstroke also return fuel to the tank, but in smaller volumes from a low pressure side regulator. Less heat and less pressure being the difference. I'm guessing that repeated high heat / high pressure cycle is the big concern for Bosch. Oxidation from heat is well noted in problems related to storing BioD in heated tanks over the winter.

Powerstroke "Dead End Fuel System"


Standard Common Rail System


Ford has since ditched the old International design fuel system in favor of common rail, so there ya go.. Even after my bad Duramax experience, I ran out an purchased another common rail engine [the MB CDI] to run on Biodiesel. I do however proceed towards B100 with a little more caution these days.

Cheers,

-Ken

This message has been edited. Last edited by: Kenr34,

Ok here is some updated CDI mileage data over a long trip, Ohio to Florida and back.

Car was fully loaded "Stuffed" with luggage and 4 passengers. Started out from Ohio running a B40 blend, headed south and refilled with dynoD at a Pilot in Orangeburg SC. My son reset the trip counter by mistake, but luckily I wrote down the start mileage.

PCM calculated 34.5mpg over last 357 miles at 77mph average.
True average at fill up was 33.2mpg over 560 miles traveled.



Return trip FL to OH on straight D2 dynoD.

PCM calculated 32.3mpg over 897 miles at 67mph average.
True average on the first fill up was 30.1mpg over 620 miles.
Outside temp was dropping fast on the return trip, 70F start and 17F when we reached the house. However that true average was mostly over flat land driving Daytona Beach to NC, with moderate to heavy cross winds.



Conclusion:
They like biodiesel, averaged 2-3mpg better on B40 blend vs straight D2 dyno diesel.
Sweet spot is about 1800-2300 RPM's, or just below 75mph, above that mileage dropped off fast on the dash average. Nothing strange to report, only you can't distinguish the smell of biodiesel running in this car. But she will blow white smoke vs black on bio.

Cheers

-Ken

I see this thread hasn't been active in a while. I am interested in running b100, most of the year living in central VA. Any updates? I am interested in b100 results not blends. I have a 275gl tote I fill up at a small plant that sells biod, actually b99 (tax brake) I havea 2006 Jetta tdi and 1996 Dodge pick up (dodge loves b99) The Jetta has run fine on it, but did have to replace the fuel tank filter, and probably mixed some not so safe biod in Fl last winter.
Utah Biod says 2005 Mercedes loves the b100(b99). This thread didn't seem to conclude much on high percentages?
Ready to start searching for this model of Benz. Just want to hear from people on hhigh blend experiences.
Thanks
George

The car I posted about above was totaled shortly after. But I purchased another 05 CDI and racked 100k miles on BioD blends with it. I can report it will run fine on B100, but you will need to upgrade all the rubber fuel line on the engine. Particularly those between hard line and fuel filter, and there to CP3 pump. While they are known to fail with age, mine deteriorated pretty quickly after I started running BioD. That was only issue.

As for B100 vs mixing. I found mine ran better, and fuel mileage was 3-4mpg greater on average if I ran about a B75 blend. I would just fill it to 3/4 tank on B100 then top it off at the station with regular diesel.

The car just hit 143k miles last week, an per a agreement with my wife, she got a new car once she put 100k on that one. Great cars, but mine is now for sale if anyone is interested...

-K

well, any links to your car for sale? kinda still kicking tires, I have a 2006 Jetta tdi, with 256k, thinking of 2005 benz but closer to 100k.
Thank you for the update. Didn't think they used the rubber hose in 2006, thought only before 2005 or so.