Impact of using LiquiMoly MoS2 on fuel economy (2004 Passat)

tikal

Veteran Member
Joined
Apr 18, 2001
Location
Southeast Texas
TDI
2004 Passat Wagon (chainless + 5 MT + GDE tune)
In my previous post regarding the city mileage of my 2004 Passat with GDE tune I had managed to collect 93 data points on a consistent route to work providing me a baseline average MPG of 36.8 via the car multifunction display (http://forums.tdiclub.com/showthread.php?t=423256). In my last oil change (5W-40 CJ synthetic like the previous oil changes) I decided to add about 250 Ml of LiquiMoly MoS2(http://www.liqui-moly.us/liquimoly/produktdb.nsf/id/us_2009.html?OpenDocument&land=US). I then proceeded to collect the same type of data for the same route between 10/12/15 and 12/18/15 yielding 37 data points with the results shown here:

https://docs.google.com/spreadsheets/d/1fuaIUC_DGm7fTkcdATe8QFH5my-TdJwThwypCfhOdLQ/edit?usp=sharing

I wanted to see if it was even possible to measure any gain in fuel economy using this methodology. Well the results somewhat surprised me:

* 100% city average 2004 Passat wagon without LM MoS2 = 36.8 MPG
* 100% city average 2004 Passat wagon with LM MoS2 = 37.9 MPG
* Gain = 3%

One could attribute the difference to the margin of error if the gain was less or equal to around 1% but at this point I cannot rule out an impact of the Molybdenum disulfide additive as a friction modifier improving FE. I cannot comment on highway mileage as I do not have a consistent way of collecting the data to make apples to apples comparison.

Anybody else with MoS2 experiences and FE?
 

tikal

Veteran Member
Joined
Apr 18, 2001
Location
Southeast Texas
TDI
2004 Passat Wagon (chainless + 5 MT + GDE tune)
I should add that the later part of my 37 data points with MoS2 the car was not in the garage but outside in the driveway. Coincidently during this time period the ambient temperatures were lower and based on the observed data points the resultant MPG for those later drives were lower. I do not think this invalidates the overall results and mileage gain. On the contrary, it makes the average mileage with MoS2 at a disadvantage with respect to my original baseline of 100% city driving without MoS2 done in the 2013-14 timeframe when the car was always in the garage.
 

tikal

Veteran Member
Joined
Apr 18, 2001
Location
Southeast Texas
TDI
2004 Passat Wagon (chainless + 5 MT + GDE tune)
Actually Central limit theorem is doing its 'job' well with the data I have collected so far for comparison purposes (percentage change). No complains.

Once the school resumes I will collect more data points to add to the 37 I already have (with MoS2) and keep comparing the MPG averages.
 

Rembrant

Veteran Member
Joined
Oct 31, 2014
Location
Canada's Ocean Playground
TDI
2013 Golf TDI DSG
Now run the same test on 1,000 Passats selected on a random basis for 50,000 miles and you might have something.
Yes, and I would add to that the tests should be done blind...that is, without the driver knowing that any changes were made or any additives added.

I think a big percentage of reported mileage improvement gains online can be attributed to the behavior of the driver. I think we'd have a lot more accurate MPG reports on here (or fewer reports overall...lol) if the car owners were unaware that any changes were made.

Theoretically speaking of course...
 

tikal

Veteran Member
Joined
Apr 18, 2001
Location
Southeast Texas
TDI
2004 Passat Wagon (chainless + 5 MT + GDE tune)
Yes, and I would add to that the tests should be done blind...that is, without the driver knowing that any changes were made or any additives added.

I think a big percentage of reported mileage improvement gains online can be attributed to the behavior of the driver. I think we'd have a lot more accurate MPG reports on here (or fewer reports overall...lol) if the car owners were unaware that any changes were made.

Theoretically speaking of course...
Good point Rembrant and I agree. When I first baselined my city mileage in the 2013-14 time frame it was done after upgrading my tune to the GDE ECO and one could say that at that time I knew of my investment (more $ than adding MoS2) and I would drive more for fuel economy to justify it. So in this scenario I think the methodology is not flawed and it is fairly 'apples to apples' comparison.


Personally I think a 3% MPG gain is generous for using Molybdenum Disulfide as a friction modifier but I keep my mind open to see what the numbers will come out as I collect more data.
 

SFHGolfTDI

Veteran Member
Joined
Nov 3, 2003
Location
Ventura, CA
TDI
2002 Jolf GLS TDI - Reflex Silver (purchased 2011) | Previously: 2001 Golf GL TDI - Indigo Blue (sold 2005)
Thanks for reporting. Remind me of what you gained with the GDE tune?
 

tikal

Veteran Member
Joined
Apr 18, 2001
Location
Southeast Texas
TDI
2004 Passat Wagon (chainless + 5 MT + GDE tune)
Update:

I collected an additional 31 points (drives to work with MoS2) for a total of 68 data points going from 10/12/15 through 3/11/16:

https://drive.google.com/file/d/0B42hSG3W3GVXWEd3by1GRmtnRWs/view?usp=sharing

My new average with Liqui Moly MoS2 changed slightly down to 37.86 MPG (from 37.9) so my mileage gain is now 2.9%. Not much difference but now I have more confidence in my estimation since I have gone through the colder season (relatively speaking for SE Texas) and the car has been the majority of this time parked outside while my previous average without MoS2 the car was parked in the garage.


I think I can call the use of my first oil additive (MoS2) in a TDI a success at this point. Looking forward other people sharing their experience.
 
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