Biodiesel-Pros and Cons - PeachParts Mercedes-Benz Forum

JimS · #1 02-22-2008, 09:35 AM

I recently purchased an '81 240D 4-speed and am considering running it on biodiesel. There is a biodiesel plant abou 6 miles from the house and we can purchase fuel there at a slightly lower price than petro diesel at the pump. The previous owner ran the car on both petro and bio. The biodiesel folks have nothing but positive things to say about their fuel. Any comments to help in the decision would be appreciated.

winmutt · #2 02-22-2008, 09:45 AM

Quote:

Originally Posted by JimS

I recently purchased an '81 240D 4-speed and am considering running it on biodiesel. There is a biodiesel plant abou 6 miles from the house and we can purchase fuel there at a slightly lower price than petro diesel at the pump. The previous owner ran the car on both petro and bio. The biodiesel folks have nothing but positive things to say about their fuel. Any comments to help in the decision would be appreciated.

Pros: "better" for the environment. Better than a newer model gasser? Hard to say. Cheaper usually. High cetane and great at lubing the car
Cons: gels at higher temps, lower cumbustion efficiency

In the winter I drive on diesel and in the summer I mix half and half. If its cheaper why not.

probear · #3 02-22-2008, 09:50 AM

The only negatives with BioD are the following:** assuming B100
Slightly less fuel mileage (less than 10% difference)
Eventually your fuel hoses will need replacing if original
Initially, you will have to change the fuel filter earlier than normal (this will go back to normal after several thousand miles)
In colder weather (sub freezing), you will need a blend because some BioD will gell much quicker than #2

On the other hand, your fuel system will be much cleaner, you will have less noticeable smoke, it usually quietens the engine, and it should run smoother.

I make and run BioD most all the time.

rrgrassi · #4 02-22-2008, 09:56 AM

Pros...cheaper than pump diesel if made yourself or if you have a good source.

Cons...swells rubber, so you will be replacing the fuel filler grommet every year.

Advice...install a fuel/water separator with a separate bowl so you can empty it. Stanadyne FM100 is a good one.

Biodiesel300TD · #5 02-22-2008, 10:18 AM

Heres my short list of the pros and cons of biodiesel as I see them
Pros:
1. Cleaner emissions (which smell better too), up to 75% less carbon.
2. Better lubricity
3. Grown in the US
4. Makes the engine run quieter and smoother
5. Close to carbon neutral

Cons:
1. Lower energy per volume than petro diesel
2. Higher NOx emissions, up to 10% more than petro diesel
3. Winter time gelling problems.

I started a quite a while ago that asked the same question, pros and cons of biodiesel, but I can't find it. I search some more and post it if I can find it.

JimS · #6 02-22-2008, 10:37 AM

1978 240D -264k - w/ a 4 speed manual, and a two tank WVO Conversion -

Andrew:

How has the two tank system worked out for you? Does it run well on WVO?

Knightrider966 · #7 02-22-2008, 01:09 PM

Well, I run pure B100 and I'm very satisfied doing so. Here's what I found out in 2 years on my 240D and my 300D as well as my Dodge Ram 4X4.
Pro's
1. Biodiesel runs much cleaner and I get through emissions with no problems!
2. Mercedes Benz and Cummins did a study from 1994 to 2000 comparing Biodiesel and concluded that it helps reduce operating costs because it is not as corrosive, it runs cleaner and after 6 years of metal particulate tests, it would not be unusual to be able to get twice the engine life from Biodiesel vs. Fossil fuels!

3. I do not have to wait in line for fuel and when I go to Western States Petroleum, I get enough to carry me through for a week or longer and just pump from my house.
4. The engine runs a lot quieter and with much less smoke.
5. The exhaust smells like food cooking! (It's amazing how many appetites I stimulate with both cars!

)
6. If you spill some on the ground, it will not poison the soil. (Millweeds however love it, it will not kill them. In fact they grow taller and bloom more profusely, so if you have millweeds you want to get rid of pouring Biodiesel on them to kill them won't work!

)
7. We spend the money on fuel here instead of sending it to other countries that don't like us. (Feed a farmer, starve a terrorist!

)
8. You help the U.S. achieve alternative energy independence while helping out National Security at the same time.

Now the Con's
1. Your actual horse power or engine kilowatt out put will be a little less, but not enough for the small difference to become a problem. Expect about a 5% reduction in performance overall. If you burn Biodiesel at 100%, then you should turn up the fuel ratio about about 1/2 to 3/4 turn and adjust your engine timing by a 2* advance to compensate. You will still get through emissions with flying colors and you will feel it in your right foot.
2. Carry some spare fuel line hose with you in the trunk. Biodiesel doesn't like organic rubber and you will need to check your injector bleed hoses and change them more frequently.
4. Biodiesel gets a little cranky at colder temps and you going to have to mix with fossil fuel or kerosene to keep it moving depending on where you live.
5. It is not as easy to get as regular diesel, so you may want to store some at home. I have a 200 gallon fuel tank for this, but I live way out in the country. Use your own judgement. If your close to the source, a couple of 5 gallon jugs could work out just fine!

The Pro's outweigh the Con's for me and everyone I met feels the same way. I haven't really noticed the fuel economy difference everyone else seems to have, but your fuel economy could be a bit less. It is still worth it though.

JimS · #8 02-22-2008, 01:37 PM

Thanks to all for the helpful comments and information. I plan on trying my first tank full of bio this weekend to see how it goes.

ajcbgray · #9 02-22-2008, 01:41 PM

What percentage of Bio can I run without having to really worry about swelling hoses and plugged up fuel filters?

beerdavis · #10 02-22-2008, 03:52 PM

I run B100 in the summer and B50 in the winter. I clogged a couple of primary filters when I first started using biodiesel. I have never had a problem with any of my fuel hoses after using biodiesel for the last 3 years. B20 is the best dilution if you do not want to worry about clogged fuel filters from what I have been told, but changing the filters is super easy.

probear · #11 02-22-2008, 04:50 PM

A couple of side notes:
First, always carry a couple of spare pre-filters. You would be amazed at the crap that #2 has in it, especially after 20 years. It probably would not be a bad idea to also carry a spare spin on fuel filter.
Secondly, ironically B100 is not a hazmat material !! BUT anything less will be because of the #2. Also, be careful of the containers that you use to store BioD. There is a plastic code that you need but I forget which it is. The yellow fuel containers work fine.

herring · #12 02-22-2008, 07:37 PM

Quote:

Originally Posted by ajcbgray

What percentage of Bio can I run without having to really worry about swelling hoses and plugged up fuel filters?

According to something I read on this site:
http://www.biodiesel.org/

B20 (or less) you can treat just like regular diesel--don't need to give it a second thought. It's concentrations above 20% where the issues start to apply.
I've not run any biodiesel yet in mine (and the previous owner said he didn't either). However, I'm the cautious type so even at B20 I'll heed the warnings about having spare fuel filters on hand when I give it a try.

NC Benz · #13 02-23-2008, 08:44 AM

Quote:

Originally Posted by JimS

I recently purchased an '81 240D 4-speed and am considering running it on biodiesel. There is a biodiesel plant abou 6 miles from the house and we can purchase fuel there at a slightly lower price than petro diesel at the pump. The previous owner ran the car on both petro and bio. The biodiesel folks have nothing but positive things to say about their fuel. Any comments to help in the decision would be appreciated.

Hey neighbor!

I usually run my two 300Ds on WVO (total of 18,000 miles on WVO, single tank). Some kero added in the winter time.

I did run some B100 for a while. A guy up the road was brewing and delivering for a REAL reasonable price. Even in the mid 20s the B100 was fine. Next year I want to have a good load of B100 for the winter.

We did need to change a fuel line on one of the 300Ds. Heed the words about primary filters. My sons car was needing a filter about every week. But in a pinch, to keep you going you can pull the filter and SHAKE OUT the gunk until you get a replacement. They are cheap, good insurance after all.

Guess you are talking to the Piedmont Bio people. Tell them I have a barrel of WVO for the to process.

retx · #14 02-23-2008, 10:45 AM

Say hi to Rachel and Leif for me. You should have no problems with their bio. Youll see, its a very professional plant.

Bio300TDTdriver · #15 02-23-2008, 11:54 AM

Quote:

Originally Posted by ajcbgray

What percentage of Bio can I run without having to really worry about swelling hoses and plugged up fuel filters?

What year is your car? The newer fuel lines last longer than the old ones. B20 is what is widely available. I don't think you will have any trouble if you only run B20.