Looks like I'll be filling up 3 gallons of Soybean oil from now on... - PeachParts Mercedes-Benz Forum

Screwdriva · #1 05-12-2021, 10:25 PM

https://www.sciencedirect.com/science/article/abs/pii/S0016236113000616

Really impressive result. 30% looks to be the sweet spot. My plan is to use new GMO Soybean oil (cheapest available option in the UK from my initial research) in my W123 and W115 diesels, given the 25% price difference here. That is, unless modifications are needed?

pawoSD · #2 05-12-2021, 11:14 PM

What they are not testing there is the long term effects on the engine and fuel system, namely coking issues. Especially in the newer CRD engine its not recommended at all. The ultra high injection pressures can pull the wax out of the fuel and do lots of bad things.

tjts1 · #3 05-12-2021, 11:38 PM

Are you reading the same abstract I'm reading? None of the results were impressive. The 30% blend was just the least bad.

shadetreemechan · #4 05-13-2021, 07:24 AM

I have been blending WVO for 15 years now. My 85 300TD has more than 250K blended miles 460K total miles with no fuel system mods.

Screwdriva · #5 05-13-2021, 07:32 AM

No way I would put that in a non-mechanical fuel injection system. Given the 25% savings over a liter of diesel here, I'll take equal performance at 30% mix. Note that Im planning on store bought new, refined cooking oil. Not WVO.

Is it true that the Indirect injection motors smoke less and run better with vegetable oil mixed in?

pawoSD · #6 05-13-2021, 04:43 PM

Have you priced out store bought refined (soybean) oil? It worked out to about $12-13 a gallon in bulk last time I checked a few years back.....

If you want better efficiency buy a newer diesel vehicle....I routinely get 30mpg+ in my GLK250, sometimes as high as 37 on 55mph roads.....and a smaller car like a VW TDI will easily surpass 40mpg.....

Over in the UK you have even more options that do way better than that!

Rogviler · #7 05-13-2021, 04:57 PM

In my 123, a bottle of canola or vegetable oil makes it run super quiet. I was worried the first time I did it, in fact. The clatter comes back once I fill up again so I don't do it since it's more expensive, though it's only about $6.50 a gallon compared to half that for diesel where I live. Can see the appeal though.

Shern · #8 05-13-2021, 05:00 PM

Quote:

Originally Posted by Rogviler

In my 123, a bottle of canola or vegetable oil makes it run super quiet. I was worried the first time I did it, in fact. The clatter comes back once I fill up again so I don't do it since it's more expensive, though it's only about $6.50 a gallon compared to half that for diesel where I live. Can see the appeal though.

That sounds pretty appealing. Are we talking a liter’s worth?
How often are you doing this?

ah-kay · #9 05-13-2021, 05:09 PM

Virgin veggie oil is same as WVO as long as it is filtered and dewatered properly. It is a known fact that veggie oil make engine runs quieter. It's a myth that WVO damages engine. 99.9% of junk cars in the junk yard were using diesel. So go figure.

shadetreemechan · #10 05-13-2021, 10:13 PM

Vegetable oil quiets diesel engines because it burns more slowly thereby effectively retarding the timing. If you are consistently running veggie oil you can compensate for this by advancing your timing and it will help performance, but you will lose the quietness.

Screwdriva · #11 05-14-2021, 07:33 PM

Quote:

Originally Posted by pawoSD

Have you priced out store bought refined (soybean) oil? It worked out to about $12-13 a gallon in bulk last time I checked a few years back.....

If you want better efficiency buy a newer diesel vehicle

Cost of diesel in the UK is £1.25 per liter. Cost of store bought GMO Soybean oil is .90p per liter.

I net 30 mpg (US) in my 300D Auto on pump diesel and 38 mpg in my 240D W115 4 speed manual. I'm happy with this.

Usaguy · #12 05-14-2021, 08:02 PM

Quote:

Originally Posted by Screwdriva

Cost of diesel in the UK is £1.25 per liter. Cost of store bought GMO Soybean oil is .90p per liter.

I net 30 mpg (US) in my 300D Auto on pump diesel and 38 mpg in my 240D W115 4 speed manual. I'm happy with this.

The mpg numbers look like uk gallons and not us gallons

Shern · #13 05-14-2021, 08:41 PM

The quieting via retarding is interesting. Tons of threads about this in the archive. I believe they started in response to the lower lubricity of sulphur free diesel, quieting the IP via lubrication, etc.

I’ve messed around with adding two stroke (or four? Can’t remember), MMO, PS Diesel kleen and probably a few I’ve forgotten, though I doubt I ever got the quantities right to notice a difference.

If anyone is actively adding soy or otherwise to their tanks, I’d love to hear your experience… and quantities used.

Rogviler · #14 05-15-2021, 12:43 AM

The ratio I had was probably about a gallon of vegetable oil to a tank, although I never fill my tank since it just spills out. Never found a filler cap that lasts more than a couple months without leaking...

When I remember I do add 2-stroke oil at half a quart to a tank. There have been arguments about whether or not the newer ULS diesel provides enough lubrication, but it certainly can't hurt.

Screwdriva · #15 05-15-2021, 07:30 AM

A bit more research shows that:

1) I'm about 15 years late to the vegetable oil revolution
2) Sunflower oil appears to be superior to Soybean for combustion (and digestion).

Fortunately, it's still 25% cheaper than pump diesel here in the UK, so will proceed with 15 liters of sunflower oil in a 65L tank, which puts me at a 23% ratio. Pump diesel has upto 7% biodiesel in it, which is why I've decided to stop there. Will circle back in a few weeks when I've driven this blend.