Over the years I've read about the beneficial properties of biodiesel (I'm referring to soybean-based biodiesel here) and am considering giving it a try in my '83 300D. Apparently there is a place nearby (Houston Biodiesel) that sells B99, although I have no idea what the price per gallon is. I have about a half tank of petroleum diesel right now, and initially am planning to just top it off with B99 to result in ~B50.

I ran a few searches to see what the possible negative side effects could be, and the primary risk seems to be that the biodiesel could dissolve my rubber fuel lines, especially the injector return lines. I also could run through quite a few fuel filters initially, but I always keep a supply of those on hand so I'm not too concerned about that. In fact I would welcome that since it means gunk is being cleaned out of the system.

Regarding the fuel lines though, about three months ago I replaced my return lines with OEM braided return lines. I assume that these should be able to withstand the bio for quite some time?

I have not replaced any other fuel lines on the car, and have no idea when or if they were replaced prior to my ownership. I have no leaks right now. Would it be prudent for me to go ahead and purchase replacement fuel lines for the rest of the system before running bio, or is this overkill?

Finally, is there anything else I should be aware of? Are there any other compelling reasons NOT to run biodiesel?

I have run BD in all my diesels for years and I have a variety of experiences with each vehicle
First,on my Benz's, I drained and dropped the fuel tanks, pulled the sending units and thoroughly cleaned and flushed the tanks to remove all gunk prior to using BD. Then all new BD proof fuel and return lines from the tank to the injectors. Finally new fuel filters were installed.
I then started BD use and have had no gunk related stalling or filter plugging. I do not know about seal longevity in the IP since I did not touch it.
The new return line you installed should last a long while, BD will slowly degrade rubber line so you will see them weeping before they completely fail.
On my TDI, I did no line replacements and and ultimately had IP seals fail
On the Cummins I did nothing and have had no issues.
Obviously you have to be careful in colder weather to avoid gelling but that is easily dealt with.
Using a known,quality ASTM grade fuel will minimize potential engine problems.
BD will quiet your motor and keep it well lubed and clean.
Good luck and enjoy your Benz.

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1981 240D 143k 4 spd manual -SOLD

2004 VW Jetta TDI 5 speed 300k -still driven daily

jdh122,

i think you've identified all the potential problems.

if you just replaced your lines with OE ones, they will be good with B100 for quite some time.

the best fuel line to use with biodiesel (when you need to replace it) is SAE J30R9. The brand I have seen is goodyear - it has a blue lining. 5/16" fits in all applications on the Benz.

the lines will slowly degrade. they wont be dry one day and leak the whole tank contents the next. when you get the bio, put some on a mason jar and throw a rubber fuel line in there. you'll see it's not instant by any means.

by far the biggest potential problem is fuel filter/strainer clogging. your inclination to start by blending is a good one. slowly increase the blend, that way you won't 'shock' the system. being proactive, I dropped my fuel tanks before running bio and had them steam cleaned. but you should be fine just starting to blend, especially if you haven't had fuel issues before.

if for some reason you are storing your car for some time (more than a month), make sure there is a high blend of petro-diesel in there. biodiesel eventually polymerizes when in contact with steel, and I would not want to leave my fuel system with bio in it long term when not in use.

dd

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'85 300D, 'Lance',250k, ... winter beater (100k on franken-Frybrid 3 Valve Kit)
'82 300D, 'Tex', 228k body / 170k engine ... summer car
'83 300TD Cali Wagon 210k, wife's car

I agree with the posts above. Have run homemade bio in two Fords, a John Deere, and two '83 MBs for several years and many thousands of miles. Just bought a Sprinter and am still researching running bio in that one. Have put about 40K miles on the MBs (with bio) and have yet to replace a fuel line. Did clog one filter each when I started running bio. Done correctly, it's a great way to go (and no veggie oil is spewing out of control in the Gulf)

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John Schroader
bio burnin' 83 300D, '83 300 SD, '79 240D
"I've never met a man who was good at making excuses who was good at anything else" Ben Franklin
"You cannot permanently help a man by doing for him what he could and should do for himself" Abraham Lincoln

I haven't started making bio yet, but I'm slowly putting the pieces together for that. I've been running bio in my Cummins truck engine off and on for years, though, with no ill effects, from B20 up to B99. I did have a filter clog when I first ran B100 in it, but no other issues ever since, and my fuel lines have yet to give me any trouble.

I just took my "new" 240D to the city yesterday for the first time, and filled her up with B99, making what's in the tank into about B50. She runs like a top, and it almost seems like she even runs a little quieter now, too.

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1976 Mercedes 240D, unknown mileage
1992 Dodge/Cummins 4WD, 284k

After all of the encouragement on here, I drove to Houston Biodiesel (which is about two miles from my house) and filled up with 7 gallons of B100 at $2.99 per gallon. This is a bout 20 cents more per gallon than the petrodiesel I would have purchased.

I've driven about 25 miles with this ~B50 blend. I could just be imagining things based on what I've previously read, but the car does seem a little quieter and perhaps shakes a little less (although my car didn't really shake that much before).

Depending on how this goes I don't see why I wouldn't continue to use biodiesel so long as it remains available locally and isn't significantly more expensive than petrodiesel. I like that it seems to be so good for the Benz, and I firmly believe that there are many good reasons to keep our dollars out of the hands of many of the oil-producing countries, so as I see it it's a win-win.

Oh, BD is definitely quieter. It has a different cetane number

I just wish there were some retailers near me. Even minor blends.

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1982 240D, sold 9/17/2008
1987 300D TurboW124.133 - 603.960, 722.317 - Smoke Silver Metallic / Medium Red (702/177), acquired 8/15/2009
262,715 and counting

Does anyone notice a difference in power output? More HP or less HP, or no change at all?

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1985 300TD Turbo Euro-wagon
1979 280CE 225,200 miles
1985 300D Turbo 264,000 miles
1976 240D 190,000 miles
1979 300TD 220,000

GONE but not forgotten
1976 300D 195,300 miles
1983 300D Turbo 175,000 miles

http://i42.photobucket.com/albums/e3...e485-1-2-1.jpg

If we had B99 in my state I'd rather burn it,than Arab oil used to blow our Boy's up.So until then its wvo for me.

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1999 w140, quit voting to old, and to old to fight, a god damned veteran, deutschland deutschland uber alles uber alles in der welt

Bio has slightly less energy content but telling by the seat of your pants will be pretty difficult. I purchased my beater last May and took a slightly different approach. I had zero records so once I cheched evything out and pulled the tank screen to find it spotless I started my slow approach to Bio. 5% for two tanks 10% for 2 tanks and so on I have about 8000 miles since May 09 and have yet to do anything to the car fuel related. That includes change the filters that came with the car. I plan on changing them at 10,000 miles. I just wanted to see what I could learn. Good luck Thanks

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83 300D 227,xxx miles, sold
86 300 SDL 130,000 miles, sold

After 40 or so miles running B50, I have noticed no change at all in performance. It still sucks.

(Just kidding - I actually find my 300D to be fairly peppy.)

Overall biodiesel has about 9% less energy content then dino diesel. (http://en.wikipedia.org/wiki/Biodiesel) you can expect about 9-10% drop in MPG.

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92 300D 2.5L OM602 OBK #59

I'm a vet - was lucky enough to get out of the military about 3 months before 9/11 so I wasn't involved in the Iraq or Afghanistan actions, but a lot of my friends were (and still are). About 8 months ago I found out that one of my best friends had been seriously wounded and it got me thinking. It was strange - I felt guilty for not being there with him when it happened. I don't know how to explain it. But it got me thinking about what, if anything, I could do to try and help or make some sort of contribution, however small. One of the questions I came up with was "why the hell am I sending these people my money so they can use it to shoot at my friends?"

'Bout a month later I had my 300SDL and another couple months of exhaustive searching later I found the Sacrament Biofuels Network. Starting my 5th month petro-free - not $1 spent on petro-diesel - and I haven't looked back once.

I just went "cold turkey" straight from petro to B100 and didn't have any problems. Changed the fuel filters after about 1 week, then again a few weeks after that. I'm not sure I understand the need to "ease" into bio-diesel. Other than its high solvent properties cleaning out the system all at once I don't know of any "shock" it'd have on the system. Your fuel filters should do just fine catching all the crud. That said, I might recommend familiarizing yourself with how to change them out (if you don't know already) and carrying around a spare primary & secondary + appropriate tools in case they decide to clog up 50 miles from home or something.

I wasn't aware that the SAE J30R9 line would work - going to look into this a bit more. Everything I've read has pointed to Viton as being the replacement of choice. But holy crap is it expensive (relatively speaking). Hell, the Autozone down the street sells the Goodyear line, for cheap! If it's usable I'm all about it. Cool. So far the OE lines are holding up just fine - no sweating or weeping anywhere, but it is on my priority list to get these all switched out with something more bio-resistant.

The car runs smoother and quieter, without a doubt. Can't really tell any difference in power, but I do get slightly lower mileage.

And call me weird, but I really love the smell. Like a hot frying pan. People who ride with me and don't know I'm running bio have asked if I have food in the car, mentioned that something smells good, etc. It's pretty cool.

S,

I switch between #2 and B99 all the time. I have a local supplier of B20 and or B99. I can say that I definitely "notice" the difference in power. Especially on take off. It is noticeably down on power with the B99.

However, it really does quiet the engine down. When we met at that first GTG I had pure B99 in there (last year). Pierre noticed how quiet it was and ran right over and asked me what fuel I was running.

AJ

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AJ

1985 300D (SOLD)

An interesting note on the power conversation here ... I work at a place that makes biodiesel and the owner drives a F-250 powerstroke that is a few years old. He says that he gets slightly better performance on Biodiesel! Weird I thought, since it has calculabaly less energy. Also, he says one of his buddies that pulls a fifth wheel trailer pretty often can't pull as well on petro diesel. I read some articles within the last couple years about some truckers that were running biodiesel in their semis that would get 6.5 or 7mpg versus 5 or 5.5 mpg on petro diesel.

In theory, I'm thinking that, the more cylinders there are, the more the lubricity aids the power of the engine versus our 4 and 5 cylinder engines which would rather have more top-end bang. Any thoughts? ... especially with the ULSD crap that is at the pumps these days.

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'82 240D 224K miles manual transmission
mods: wooden 4by4 bumper, EGR delete and older EX manifold without EGR port, glass pack muffler (cheapest replacement muffler), rebuilt bosch injectors with Monark nozzles

working on: aux electric fuel pump, coolant/fuel heat exchanger/filter head, afterglow, low oil pressure buzzer/LED