Why does biodiesel make the engine more quiet than petro diesel?

[Biodiesel300TD]

Why do diesel engines run more quietly on biodiesel than on petro diesel? Is it due to the better luberocity of the bd? Just wondering what causes the difference.

Andrew

[TheDon]

better lubricating qualities higher cetane value

[MarkM]

I dont run biodiesel, and currently have no plans to convert, but if biodiesel runs so much better, what minimum percentage of veg oil will show this benefit...what if I put in a quart of mazola with every fill up? This would only be a little less than 2%

Thanks,

mark

[Mike J]

Originally Posted by Biodiesel300TD

Why do diesel engines run more quietly on biodiesel than on petro diesel? Is it due to the better luberocity of the bd? Just wondering what causes the difference.

Andrew

Better lube, cleaner burn, higher viscosity.

[Diesel Giant]

I am sure there s a chemical reason but I am not at liberty to say.

[Ra_]

Originally Posted by MarkM

I dont run biodiesel, and currently have no plans to convert, but if biodiesel runs so much better, what minimum percentage of veg oil will show this benefit...what if I put in a quart of mazola with every fill up? This would only be a little less than 2%

Thanks,

mark

Biodiesel is a little different from straight veg oil.
Biodiesel has been processed to remove the glycerine from the oil.

[junqueyardjim]

Regarding MARK M's question about adding one quart of VO, it makes a huge difference. Instantly the engine is smoother and quieter. That is how I first went about using VO. Started by buying new VO by the quart, liked it so much that I lined up a couple places where I could get WVO, and have been running it cold all summer until the middle of October, quit because of dropping temperatures. Of course running cold WVO is so good that I ran it straight, adding only a quart of gasoline to each 5 gallons of WVO. But I get the same smooth quietness running the local Co op biodiesel, which I think is only 1% bio. The 1% bio I think has about the same "feel" as 1 quart of VO in the tank full of diesel

[83-240D]

blondie has a grease tank. she runs better on straight wvo than on any petro product. like others have said above better lubricity of the pump and engine parts. on the wvo thye car also has more power to pass on the hwy.

you do not have to convert to run bio d. bio d goes into the main tank. if you live in a cold weather climate like i do then you must have a 2nd system for the grease. as little a blend of 2% bio d in the tank will make an immediate aural difference. a qt of oil from sams or wally world will do the same.

markm if you do decide to run bio d first look at the age of the rubber fuel lines under the engine. bio d will soften them. if they ar getting old replace them. then check the return lines. if they are black they are prolly seeping diesel and need replacing. after doing that you are free to run bio d safely. be sure to carry spare primary filters as the bio d has a cleansing effect on the tank. your car will thank you.

[TheDon]

next year when the hurricanes come im going to costco and buying as many 5 gallon jugs of veggie oil i can along with as much biodiesel i have ill store.. so when i run out of bio ill run virgin svo

[ConnClark]

Bio Diesel and veg oil have slightly lower energy and are slightly less combustible so you get less of a knock when they start to burn. This makes the engine run smoother. You get more BTUs from dino diesel hence the reason people tend to get slightly better milage from it.

[pmari]

Absolutly, unless your IP is noisy as hell, lubrisity won't quite down combustion/detonation noise. I still haven't seen the exact reason why plant oils and plant oil esters decrease detonation sound. I have seen it specualted that it's due to a lag in detonation and longer burn times.

Originally Posted by ConnClark

Bio Diesel and veg oil have slightly lower energy and are slightly less combustible so you get less of a knock when they start to burn. This makes the engine run smoother. You get more BTUs from dino diesel hence the reason people tend to get slightly better milage from it.

[DieselAddict]

Higher cetane is the only reason why a car on biodiesel runs quieter. Cetane is the combustibility of fuel. The higher the value, the less delay there is after the fuel is injected before it ignites. And the sooner it ignites, the more gradually it burns (there's less raw fuel when ignition begins). Thus you get less knock.

[83-240D]

Originally Posted by ConnClark

Bio Diesel and veg oil have slightly lower energy and are slightly less combustible so you get less of a knock when they start to burn. This makes the engine run smoother. You get more BTUs from dino diesel hence the reason people tend to get slightly better milage from it.

yep. petro btu aro 135,000 per gal. bio and wvo aro 121,000.

[pmari]

Then how do you explain striaght vegtable oil with a cetane value of 38 running quiter than petro diesel with a cetane 50+ ?

Originally Posted by DieselAddict

Higher cetane is the only reason why a car on biodiesel runs quieter. Cetane is the combustibility of fuel. The higher the value, the less delay there is after the fuel is injected before it ignites. And the sooner it ignites, the more gradually it burns (there's less raw fuel when ignition begins). Thus you get less knock.

[DieselAddict]

Originally Posted by pmari

Then how do you explain striaght vegtable oil with a cetane value of 38 running quiter than petro diesel with a cetane 50+ ?

It should be the other way around. Petrodiesel typically has the minimum cetane of 40 as mandated by ASTM. VO has a much higher cetane.