Fuel Dilution: ASTM D3525M or Flashpoint?

Messages
832
Location
98245
I took 2 samples for my most recent UOA, sending one to Blackstone and the other to a guy I know who works in another lab. Results from the 2 labs were close except for one parameter: fuel dilution. NOTE: The numbers below are in percent, but the message board won't let me use the percent character. Blackstone measured under 0.5, lab X measured 2.1 I called blackstone and they said they estimate fuel dilution based on flashpoint. Lab X uses ASTM D3525M (whatever that is). Lab X says flashpoint is an inaccurate way to estimate FD because oils can boil off the low BP components giving higher flash points and false negatives on FD, or they can decompose into lower FP components giving false positives on FD. Lab X says 2.1 is "normal" for D3525M measurements on oil from motorcycle engines like mine, and Blackstone says 0.5 is normal for their measurement, so either way there's no problem. But there is a big difference between Blackstone's 0.5 and Lab X's 2.1. Any insight from the board here? Thanks,
 
Messages
2,095
Location
IL
Wow I had no idea Blackstone's fuel % was an estimation. Seems it would open the door to many inconsistencies and innacuracies? But I think we would be surprised...I doubt many actually do full testing on certain things. Schaeffer lab doesn't do fuel test unless viscosity is below grade. But they still report it as zero fuel, so you'd think they tested it if you didn't know better.
 

MRC01

Thread starter
Messages
832
Location
98245
quote:
Originally posted by Patman: ...if I specifically request the fuel dilution test, they report it exactly how it is...
Do you know whether they use ASTM D3525M, estimate based on flashpoint, or some other method?
 
Messages
47,824
Location
Everson WA - Pacific NW USA
I have to agree that the Blackstone estimated method sounds inaccurate at best. I need to inquire as to the method OAI uses. The person from Blackstone posts here from time to time, perhaps you can email them and ask that they respond publicly to your post. I'm not throwing rocks at Blackstone (I have recommended them) but it seems I don't really like their TBN method and now this estimated flashpoint.....
 

Patman

Staff member
Messages
22,012
Location
Guelph, Ontario
quote:
Originally posted by MRC01:
quote:
Originally posted by Patman: ...if I specifically request the fuel dilution test, they report it exactly how it is...
Do you know whether they use ASTM D3525M, estimate based on flashpoint, or some other method?

This is what their website states: Dilution Dilution of a use engine oil can be measured precisely by gas chromatography (GC) or by Fourier Transform Infrared spectroscopy (FTIR). More common is the use of the SETA-FLASH tester, where the flash point of oil is tested by a certain temperature. When a flashpoint is detected, the dilution is heavy (more than 4%), when not, the dilution is acceptable (less than 4%). It is evident that heavy dilution of the oil is unfavourable for the engine, since it involves a lower viscosity and reduces the resistance of the oil film. The principal causes of dilution are a defective fuel injection system, a defective air inlet (obstructed air filter), incomplete combustion due to too low a working temperature, and badly regulated valves, or insufficient compression. So if I don't specifically ask for fuel dilution to be tested, they estimate it, but if I ask specifically, they do it precicesly by gas chromatography.
 

Patman

Staff member
Messages
22,012
Location
Guelph, Ontario
If you don't specifically ask for a fuel dilution test from Wearcheck Canada, the report will come back saying "less than 2% fuel" but if I specifically request the fuel dilution test, they report it exactly how it is, and with those tests I usually see 0.0%, but on my last uoa I saw 0.5% because of my starting problem and my wife's wintertime UOA showed 1.0% fuel.
 
Top