Use of Diesel Purge While Under Load? (Effectiveness, MPG?) - PeachParts Mercedes-Benz Forum

Shawn D. · #1 04-17-2007, 09:45 AM

Y'all,

I've picked up two 500ml cans of Lubro-Moly Diesel Purge and am planning to purge soon. From all the posts I've read here about the process, it looks as if everyone does this at idle (or running the engine at various speeds) and not under load.

Has anyone done it while under load (i.e. actually driven the car)? If so, did it seem to make any difference in its effectiveness? How quickly was it consumed (i.e. what was the effective MPG relative to the car's normal MPG)?

My point in asking the MPG question is to determine whether the 1L of Diesel Purge will allow me to make at least one jaunt around the neighborhood and get back home before the reservoir runs dry and the IP sucks air. My 300td normally gets 27 MPG, so will the 1L (0.25 gal.) of Diesel Purge allow me to make a two-mile loop around the neighborhood with a safe margin?

Thanks in advance,
Shawn

vstech · #2 04-17-2007, 09:56 AM

Dieselgiant's website states just this, it will be enough to drive around.
check out his writeup.
John

bodyart27 · #3 04-17-2007, 10:24 AM

On my last spin-on fuel filter change I refilled it with diesel purge. I puttered around the block (no hard turbo boost) to speed up the process. Can't tell you how long it took to go through (plus diesel fuel was probably instantly being mixed in to the fuel filter).

I'm not sure what the effect would be of getting on boost with just pure diesel purge, however, I wouldn't be surprised if the engine could handle it based on the crazy types of fuel this care can use.

neptune · #4 04-17-2007, 12:08 PM

1L of diesel purge should get you several miles of driving easily.
I recently ran one 500mL can through my sister's 240D, running it at idle then higher speeds once warmed up. It took at least 20 minutes to run the single can through, probably more. I had time to nearly finish changing the oil on another car while it ran through.
I would have driven it around if I would have had enough hose and a plastic container for the diesel purge. I had a glass jar and not enough hose to securely mount it in the engine bay, so I didn't feel comfortable driving it.
You should be fine.

pawoSD · #5 04-17-2007, 12:41 PM

Heck I have driven around on nearly pure Marvel Mystery Oil!

(and diesel purge too)

lonewolftek · #6 04-17-2007, 01:30 PM

I've driven as far as 4 miles, on two cans of Diesel Purge.

The first time I did it, when the turbo kicked in I saw a lot of smoke coming out the tailpipe and started to worry. Got down off boost, puttered home, hooked it back up to the main tank, have had zero problems since then.

TMAllison · #7 04-17-2007, 01:36 PM

27mpg/3.6L = 7.5 miles per L

I personally like to start up on DP cold, let warm up, raise rpm a few times and then shut down and let it sit overnight to soak. Next morning I burn the remaining 1.5 cans.

davidfaulk · #8 04-17-2007, 01:45 PM

I always take a little drive during a purge. My next door neighbors are glad that I don't sit in the driveway revving the engine for 20 minutes. As you drive, make sure to pull over every couple of minutes or so to check the level so you can start heading back when it's near empty. As you coast, put it in neutral and rev the engine occasionally.
I didn't notice any benefits from the purge but I'm sure they were there. I put in a 2nd inline filter (cheap VW type) in front of the prefilter just before I started purging and it turned from yellow to black by the end of the day.

Shawn D. · #9 04-17-2007, 05:14 PM

Thanks for the inputs, folks! I think I'll take a little round-the-neighborhood trip on Diesel Purge.

Quote:

Originally Posted by TMAllison

27mpg/3.6L = 7.5 miles per L

Uhh... yeah, I know how to do the math.

Getting 7.5 miles per L on diesel is different from getting ?.? miles per L on Diesel Purge, though.

TMAllison · #10 04-17-2007, 05:20 PM

You ought to get more mpg on DP as its cetane rating is greater......

pawoSD · #11 04-17-2007, 05:26 PM

Quote:

Originally Posted by TMAllison

You ought to get more mpg on DP as its cetane rating is greater......

That, and the fact that DP is about 60-70% diesel.

Cervan · #12 04-17-2007, 07:48 PM

i would use it hard as possible. meaning dont floor it in neutral go to a stoplight and put the petal to the floor if you have a long incline floor your car the whole way make sure you dont do it on the way down though... basically when your engine is under load it will clean up best.

2.5Turbo · #13 04-17-2007, 09:41 PM

That's what I did when I ran some DP through mine. Putting the engine under load increases the combustion temps and in theory should increase the effectiveness of the DP. I did my DP runs on this big hill on a side street by my house. I just coasted down and floored it to the top many times until the DP was near gone, pulling over every couple runs to check the level. Be sure your container is secured to something on the inside of the engine compartment, and that you have the tools necessary to hook your fuel lines back up if you accidentally run it dry.

Shawn D. · #14 04-17-2007, 10:47 PM

Thanks again for the inputs! I have a few moderate hills I can traverse, and I will definitely secure the container and carry tools with me (I'd already figured that much!).

toomany MBZ · #15 04-17-2007, 11:40 PM

[quote=Shawn D.;1482314]Y'all,

From all the posts I've read here about the process, it looks as if everyone does this at idle (or running the engine at various speeds) and not under load.
IIUC, there is no difference between various rpm, the way I do it, vs driving around, under load. The only problem would be you cannot tell if you're going to run dry. The engine does not know if the car is moving.