Hello everyone! I run a dirt modified on circle tracks in NY and PA. I'm new to this class, but I've been involved in racing my entire life. What I am also new to is synthetic racing oil. In the past, I've always run either Kendall or Valvoline 20w50 racing oil. We always changed oil at least every other week. I'm not sure if this was necessary, but that's what we always did. Now I am running Amsoil's Dominator 15w50. It seems natural that you wouldn't have to change synthetics as often as dino oil, but I can't find any actual recommendation. I have heard of people running entire seasons on synthetic, but I don't know if this is a good practice. Really, I don't think I am being that hard on the oil. The engine is a Chevy 358 with a roller cam. Per the rules, I am only running 6000 rpms. I've only run it once and got the water temp up to 180; I do not have an oil temp gauge. The former owner said he didn't get it much warmer than that. It has a circle track oil pan with an approximately 7 qt sump. The filter is a Wix 51069R. It is run on VP 110 leaded racing fuel through a Holley 2 barrel carb. I don't know that much about this engine, as I bought it as is and haven't had it apart. On a typical race night, I run about 35 laps between practice, heats, and features. This is at tracks from 1/4 to 3/8 mile. I am currently debating if I'm going to stick to one night a week or move to two. So what do you all think? I'm sure a UOA is the best answer, but I am new to this stuff and not sure about everything involved. What is a typical turnaround for a test? Since I am kind of week to week, I can't really wait a month for test results. Thanks for any help.