I don't do 3K or use the olm yet. I started with a 5K oci and got a uoa. I'm going to work up from there to see what is reasonable.
The olm is probably fine if you use synthetic and have no engine issues. The olm calculates, but doesn't actually measure, so I do a uoa every year or so to check for coolant leaks, proper air filtration etc. anyway.
OLM is good for keeping you from skipping an oci and is a good tool when combined with an occasional uoa. Since it doesn't tell me anything about the efficiency or condition of my air filtration , doesn't know that I run GC 0W-30, or doesn't know if I have an internal coolant leak etc., I take it for what it is worth.
No way would I go by the OLM with generic cheap dino.
Like Patman, I might eventually be able to go by the OLM, but verified by uoa and I use GC.
I have a Series II 3800, V6. Each GM engine will be different and as BMW's OLM implies, also has a lot to do with the amount of fuel consumed.
[ January 05, 2005, 02:22 PM: Message edited by: haley10 ]