MPG's (difference with bio D vs. SVO vs. regular diesel?)
 

Will your vehicle obtain better MPG's by using Biodiesel or even straight vegetable oil, rather than running on regular diesel??

Bump

diesel is a funny thing. when they went to super low sulphur, we all suffered loss of MPG.

look at this chart, then consider diesel now has less btu's then when it was written.

Biodiesel Fuel

Good link. So according to that info, 7-10% drop in mpg due to bio-fuels. What percent BTU drop is ULSD compared to LSD?

People I've talked to said that they didn't notice any drop in mileage, due partly to the added top end lubrication of bio-diesel.
But even if it's a 10% drop in mileage (haven't heard anyone have that happen) it's still a 100% reduction of petroleum diesel and oil crops produce enough oil that farmers can grow their own fuel, press it on site and come out ahead, from what I remember energy input in to making bio-diesel was less then 10% of what you get out of it, corn ethanol is no where near that efficient.

actually, biodiesel is MUCH more expensive then ethanol to produce. Biodiesel is from oil - takes a LOT of plant oil to make biodiesel.

ethanol is starch/sugar. lots of starch/sugar in plants. that is the reason ethanol is so much cheaper to buy then biodiesel.

If they stick to rapeseed , that is.
There are plants that yield far more oil than rapeseed or soy.

Ethanol also gets huge government subsidies, around 50-70 cents per gallon? the person who told me that bio-diesel was not very energy intensive to produce was a farmer who has been growing oil crops for bio-diesel for a number of years now and they wanted to find out for sure how much energy it took them to produce their fuel so they kept records of all the fuel used to produce the fuel they used on the rest of their farm along with electricity used to run the press and all of their other inputs, I wish I could find my notes, but it was a tiny amount of energy was going in to their fuel.

When I would process WVO for use I put almost no energy into it, just a little time.
Even then when Diesel was around $3/gal I could produce at least $30 worth of fuel per hour spent on it, bigger batchs yelded a higher $/hour number, over $40 per hour sometimes.

I don't believe that. Making biodiesel is a very simple process with cheap materials. Ethanol requires large amounts of water and energy to make.

I get slightly better mileage with biodiesel; I attribute that to higher cetane as the energy level of B100 is very close to ULSD.

I think there's a little confusion here about the cost of making biodiesel vs. ethanol.
Making biodiesel or WVO from free used cooking oil is very cheap. $1/gal?

Making the un-used cooking oil is much more expensive.

If you had to make the oil from raw products, then refine it to biodiesel, then it would be $8+/gal.

To answer the OP's question about MPG and biodiesel; yes, it's not as good as petro diesel. I've seen 1-5% worse and 4-10% worse. Lots of variables there. I've been running B100 for 6 months now and B99 for 2 years before that and my driving style blocks any good study, but the difference is marginal. I know marginal is what hypermiling is all about, but once I started making my own fuel, I cared less about MPG and more about that cool smell that followed my truck around. :)

-Kevin

I have been considering making biodiesel from WVO for a while now since the price of producing it far outweighs any slight reduction in mileage I may see. My main concern is this:

Does biodiesel have any effect on the lifespan of the injection pump?

In short: No.

Biodiesel doesn't hurt the IP (injection pump) or any of the parts of the whole vehicle. Byproducts like soap, unconverted oil, and leftover chemicals from the reaction or process do hurt the IP. There's about 5 tests that I do along the way during the process to insure that I have the best possible fuel, and it's easy to see how some of these tests are never done or neglected along the way.

If you have a 1982 Merc 240D, then you'll be fine with sub-standard fuel. If you have a $40k modern diesel with common rail injection make sure you're doing it right. My truck will produce 26,000 psi in the fuel rail and has 4 timed injection moments during each cycle. This is part of the reason it's so quiet, efficient, and clean. (as are most modern diesels).

Substandard production is the real reason behind failures. I admit that I spent years reading about biodiesel before I designed and built my processor. But I love it.

-Kevin

This has got me curious, and after looking into it a bit more it seems that biodiesel is actually better for your injection pump than regular diesel. Apparently, the more they reduce sulfur content the more it reduces the lubricity, which doesn't bode well for the ultra low sulfur diesel they have now. Just one more reason for me to start making my own.

How much of the cost advantage of waste vegetable oil or home made biodiesel come from the lack of taxes, and markups at the pump on a per btu basis?

I drop about 1 MPG with bio-D but the engine runs much smoother.
I've been told by mechanics it cleans deposits out as well.
Ancedotally I've read on the internet it can swell pump head seals, stopping small leaks.
I accept the MPG loss for the overall enviromental benefit. I think they process it from soy around here.locally grown is always better :-)

I have a friend at a local fuel supplier. He was mixing bio with regular diesel to deliver to a customer. The bio hose was sort of gunky on the outside, he said they needed the right hose, that this rubber didnt stand up to the 100% biodiesel.

Did you have to change anything on your vehicle (hoses?). His hose may have been a cheap one I dont know.

I dont know what they made the biodiesel out of either, maybe that makes a difference?

this is the entire key to biodiesel.

Biodiesel is aggressive and will destroy seals, hoses etc. I once had my fuel lines destroyed within a single tank...

However, there are materials that can cope with biodiesel. If you're lucky, your car is equipped with those. If you're not, then you have to replace fuel hoses and seals in the injection system with their more resistant counterparts (look for "fluoro rubber", "fluoro caoutchouc" or the trade name "viton").

I think that is what he said they needed now that you jogged my memory "vitron".

While I was thinking, I wondered if the commercial stuff isnt filtered and rinsed as good. The gunk had a soapy look to it and it was an old rubber hose, not new.

I am curious for my tractor, but I only burn 20-30 gallons a year in it. Its a newer John Deere 5103 so maybe it has the better hoses.

Marc- Modern diesels that can run low-sulfur dino diesel should be good for Biodiesel. I had to replace hoses on my '82 240D but my '03 TDI Bug has 100k on b99 and the fuel lines are fine. I did have to replace my fuel filter more frequently when I was buying crap biodiesel. Got so I could do it on the side of the road in 10 minutes...

It should be ok then, its only 5 years old. As for running out, its a tractor, I dont really worry about traffic. :D

It gets used to plow the garden, mow and in the winter plow the road. Have you tried the additives that keep desiel from gelling? What do you use in bio-d?

Additives...
 

I live in SF, it doesn't get cold enough to need any additives. Unless I drive to Tahoe.

-PaulK

B20-B100 in an 06 Jetta TDI 1.9 PD
 

As for the OP, I have run homemade bio for the last 8-9 yr. Mostly in my 96 and 98 Dodge diesels. I also have run lots of it in my 06 Jetta.

As far as MPG and % of Bio, I found that the Jetta got its best MPG from B20- B50. After that it started to fall off a bit until I was down below my D2 MPG at about B60-B70. On B100 I was about 3-4 MPG lower than D2.

So, if the price of D2 and B100 were the same then B20 would be the best option. But, with D2 double or maybe triple the cost of home made B100, it is really not a matter of money but how much free time I have to make it (time is money LOL).

I think that the improved MPG is not only due to the better lubrication, but the higher O2 content of Biodiesel that allows for a more complete combustion. My 98 Dodge will black smoke if you get on it too hard if it has D2, but the same hard acceleration with B100 will only give a slight haze. MPG in the Dodges do not seem to be much different D2 or B100, maybe because they don't get more than 20 MPG on a good day.


Dieseltim