evidence AGAINST short oil change intervals


Top Post Dawg
Aug 3, 2003
West Des Moines (formerly St Paul)
2003 Jetta TDI wagon, silver; 2003 Jetta TDI wagon, indigo blue; 2003 Golf GL 5-spd, red (PARTED); 2003 Golf GLS 5-spd, indigo blue (SOLD); 2003 Jetta TDI wagon, Candy White (SOLD)
Regarding particles <15 microns vs >15 microns...

If you are mainly concerned with the larger particles, then just pay attention to the smaller ones. They will never be uniform in size, even in a typical UOA showing Fe of 30 ppm after 10k miles (which would be an excellent UOA result), there would be an unknown number of larger particles that aren't counted. If the Fe count was 80 ppm, then the number of larger uncounted particles would likely be greater.

So my point is that using a particle count method of testing isn't necessary -- just run the normal tests and as long as the numbers are reasonable, then the engine is probably pretty healthy. If I am wrong, then George or TooSlick or one of the other experts will likely let me know.