i used conventional on my ka24de I just rebuilt. I changed the oil after the first 100 miles, then changed again on 400 miles, I started beating the piss out of it after 400 miles, and Ill let you know how it holds up if another thread opens up like this or something goes wrong. I have since at 500 miles drifted around one night for like 20 minutes beating the piss out of it and brought it up to 5000-5500 rpms a couple times on the road 2. well see if its alive and well at 2500 miles....and what the compression test is