shran,
i would never change oil on a old school turbo gas engine at 6k. good to know it is possible a lima wont eat or burn oil with a lima at 6k. i have never seen a turbo lima that did not eat oil but they are also mostly higher performance application and catch canned so it is a given in general. that is a tight engine. very impressive. we have had oem birds and stangs in the family and they would be getting to the add mark before 3k and gobble oil after....just like my windsors....and that was running mobile 1 full synthetic.
it is one of the criticisms of the ls platform and gen 6 gms. they eat oil with those atrocious pcv systems...seems that would not be emissions friendly... the ring packaging ect is why i dont run the rotella and stay with the full syn 5/30 dexos. and the reason i only use the rotella in a older 10-30/ 10-40 application...
This is just a stock Lima 2.3 from 1988... naturally aspirated... one full rebuild on the clock. I've got just a hair over 50k on it - has been about 10 years. I was really careful about running good oil for the first few years but it's burning a bit now and so I stopped caring and just dump whatever I have on hand into it and change it every 6k. Last oil change, that was a couple quarts of 10w40 semi synthetic and 3 quarts of 15w-40. It burned a quart by the time I hit 2000 miles so I continued filling it with 15w40.
The reason I am at 6000 miles oil change intervals is because that is when I rotate my tires.... I get all the maintenance done in one shot. I think 3000 miles is a waste with modern oils. 10K or more or whatever they advertise now is stupid IMO - that's a lot of time for the average owner to forget about changing it entirely and run it out... I also think that is why we are seeing Kia & Hyundai engines getting ruined from oil starvation, people don't check it and then run them forever between changes + some inherent oil burning = disaster.
Agreed about the GM engines. Our service truck, my in-law's half ton, and my buddy's 2500 are all the 08-13 body style and they use a shit ton of oil. The 2500 has a 6.0 and started burning over a quart every 1000 miles. There was no PCV valve on that engine that we could find - just a baffle in the valve cover, and a hose that runs straight to the upper intake.