Author Topic: OMG!!! 560hp/980tq IDI!!! (Read 6080 times)

zagarus · « **on:** February 03, 2007, 02:37:48 am »

now that i have your attention :lol: i need to get this cleared up...

Why is my mileage not so great!!!! it really annoys me when i know i should be getting better.

I just filled up 19litres, and had only driven 250km. thats like mid 30's!!! and on top of that i just recently had new GTD nozzles installed and the power is noticeable, but mileage seems unaffected.

Does anyone think its the ULSD thats the main reason, or is there something else? And yes down the road i plan on a Giles pump.

someone make me feel better...it saddens me to see my car loose its main quality (great economy) :cry:

Op-Ivy · « **Reply #1 on:** February 03, 2007, 04:03:09 am »

Hmm... I have the same problem. I get around 37-39mpg... No clue why either. I know my breaks in the front are rubbing a bit but I dont think its noticeable enough to cause low mileage like that.

I dunno about the ULSD... Power loss is only supposed to be approx. 1%

BUT! I let my car idle in the morning for a good 5-10 minutes because of the cold weather. Over a few weeks I'm sure this will add up. So I'm sure thats a contributing factor.

zagarus · « **Reply #2 on:** February 03, 2007, 04:09:57 am »

lol good point matt, but i heard the best thing for a car in the cold is to drive it slowly, keep it low revs until it warms up, just idling i heard isnt a great idea.

but ya with the brakes, im hoping once i get new wheel bearings all around and my coraddo brakes this month there will be some difference,

Typrus · « **Reply #3 on:** February 03, 2007, 11:00:03 am »

ULSD also has a significant drop in lubricity. That was the whole purpose of the Sulfur. Its slippery stuff.
Less lubricity=more friction=less efficiency=worse mileage and less component life.
Our 1Z TDI was getting 44mpg. Couldn't figure out why. Our Ford Excursion 7.3L Powerstroke was getting 16. Couldn't figure out why. So, we went to Wallyworld, bought a huge bottle of Power Service lubricity boosting additive, put it in both, and mileage in the Ex shot up to 18 and the 1Z to 46, both consistent over 2 tanks so far.

Try a quality additive, Stenadyne being way up there. Longer Diesel Life and Power Service also work well.

Turbinepowered · « **Reply #4 on:** February 03, 2007, 11:16:49 am »

Quote from: "Typrus"

ULSD also has a significant drop in lubricity. That was the whole purpose of the Sulfur. Its slippery stuff.
Less lubricity=more friction=less efficiency=worse mileage and less component life.
Our 1Z TDI was getting 44mpg. Couldn't figure out why. Our Ford Excursion 7.3L Powerstroke was getting 16. Couldn't figure out why. So, we went to Wallyworld, bought a huge bottle of Power Service lubricity boosting additive, put it in both, and mileage in the Ex shot up to 18 and the 1Z to 46, both consistent over 2 tanks so far.

Try a quality additive, Stenadyne being way up there. Longer Diesel Life and Power Service also work well.

Misconception. Sulfur is not a lubricating agent of any significance in a diesel fuel.

The resultant lesser lubricity in the fuel is, however, a result of the process that removes the sulfur. During some point in the sulfur stripping process, valuable lubricating compounds are damaged or similarly stripped, resulting in reduced lubricity. This is also why the lubricity can vary from batch to batch at the refining stages, even though the sulfur content remains the same.

Also, to be ASTM certified all ULSD must be treated with lubricity additives to bring it up to pre-ULSD lubricity standards or beyond prior to being delivered to the end consumer.

This is not to say that you should not run the lubricity additives, however; there is no such thing as "overlubrication" when it comes to parts that rub against each other potentially in excess of 8000 times per minute!

foxracer1 · « **Reply #5 on:** February 03, 2007, 11:25:03 am »

Quote

Misconception. Sulfur is not a lubricating agent of any significance in a diesel fuel.

The resultant lesser lubricity in the fuel is, however, a result of the process that removes the sulfur. During some point in the sulfur stripping process, valuable lubricating compounds are damaged or similarly stripped, resulting in reduced lubricity. This is also why the lubricity can vary from batch to batch at the refining stages, even though the sulfur content remains the same.

Well said I was thinking this exact same thing as i was reading this post. Many people think the sulfer is good it is just along for the ride in the fuel serves no purpose. Sulfer is why in heavly populated areas you get acid rain sulfiric acid. Now get it out with out losing the good fuel properties.

Turbinepowered · « **Reply #6 on:** February 03, 2007, 11:25:39 am »

Quote from: "libbybapa"

ULSD is thinner than the older versions. The dynamic timing advance depends on internal pressure to operate correctly. Internal pressure is created by the vane pump pushing fuel into the injection pump and the specifically sized "out" orifice resisting the flow of fuel out of the pump. That system does not compensate for changes in the viscosity of fuel. Obviously if the viscosity of the fuel is less, the internal pressure will not build as quickly and the dynamic timing advance will be progressively retarded with rpms. The lack of proper dynamic injection timing will result in decreased performance and fuel economy regardless of the BTU content of the fuel.

Wonder if anyone's looked into the resizing needed to return that orifice to its proper relationship with the fuel's viscosity. Or, instead, looked into one that would be appropriate for ASTM spec (to establish a standard) B100/B99.

Typrus · « **Reply #7 on:** February 03, 2007, 11:34:29 am »

Sorry, was just going off of everything I've read. Whether its right or not... No idea now. I guess more research is needed, eh?

I wonder what the comparison between ULSD and Biodiesel is in terms of viscosity? Its possible that they are similar enough that the small mileage drop seen in Biodiesel from previous fuels could now be insignificant or even reversed? Someone had best clear this up with me, because its indeed a good though in my mind. I haven't paid much attention to the BD circles for Powerstrokes in the area of late, but I know people who had gotten 18 were getting 17 or so with B100 and now people who were getting 18 are getting 15 with this ULSD winter blend. Compared to 17 with previous winter blends.

SMOKEYDUB · « **Reply #8 on:** February 03, 2007, 12:27:29 pm »

DAMN THOSE MISLEADING TITLES!!!!!!!! lmao

jtanguay · « **Reply #9 on:** February 03, 2007, 01:12:47 pm »

what a way of getting our attention... you get me all hyped up for nothin!!! :lol:

Quote from: "libbybapa"

ULSD is thinner than the older versions. The dynamic timing advance depends on internal pressure to operate correctly. Internal pressure is created by the vane pump pushing fuel into the injection pump and the specifically sized "out" orifice resisting the flow of fuel out of the pump. That system does not compensate for changes in the viscosity of fuel. Obviously if the viscosity of the fuel is less, the internal pressure will not build as quickly and the dynamic timing advance will be progressively retarded with rpms. The lack of proper dynamic injection timing will result in decreased performance and fuel economy regardless of the BTU content of the fuel.

Andrew

andrew you're just full of very useful information!!! that explains a lot. so basically to compensate for ULSD our pumps should be calibrated on a test bench so that the dynamic timing advance is bang on?! seems like it could be the reason why i'm getting such poor mileage.. (38-40mpg range)

yea sulphur is pretty much good for one thing... fart bombs :lol:

and i will second that adding lubrication to your fuel will increase pump life and reduce parasitic friction losses which should increase mileage. most of those additives increase the cetane number which also increases mileage

i've just got my little fuel pump in the main couple days ago and need to install it... should make the car idle a wee bit smoother

Benjamin · « **Reply #10 on:** February 03, 2007, 02:48:38 pm »

wow guys, sounds to me i need to read this twice, dreaming a night about it, problebly i understand it all next week with my poor english :lol:

what the hell is a ULSD, how to change this? my mileage also need to get better, with driving like a *** 110km/h i get 6,7l/100km, normal driving with my 60hp in the city makes 8l/100km :?

there need to come a DIY/How To about making better mileage.

Greetz, Benjamin

Turbinepowered · « **Reply #11 on:** February 03, 2007, 03:07:06 pm »

ULSD = Ultra Low Sulfur Diesel, also known as 15ppm Sulfur diesel.

I think you guys in Europe already have it, and have for quite some time.

zagarus · « **Reply #12 on:** February 03, 2007, 03:42:35 pm »

haha i titled thsis good didnt i hahaha.

So as was said before with the dynamic timing being different due to the less volume if you will fuel, then is it possible to readjust the timing of the fuel pump to match up better as it was before the new diesel?

Slave2School · « **Reply #13 on:** February 03, 2007, 03:52:46 pm »

It might be easier to add 1L/2stroke per tank or canola oil or something like that to thicken it back up

zagarus · « **Reply #14 on:** February 03, 2007, 04:06:11 pm »

i know adding something should help, and ihave been adding an additive every time i fill up. It just doesnt seem to make a difference.