Hi. Long time reader first time poster. I have a 2k Celica gts which I take to the track occasionaly. The manual recomends 5w30 and 10w30 grade. I instaled an oil temp and pressure gauge. For temp readings, I placed the sender at the oil pan. The oil regularly reach 260F+ and I've heard the temp should be significantly hotter in the bearings and cylinders. Engine rpm dwells at 5-8k rpm for 25min durations. I'm currently using M1 and sometimes Redline 10w30. I'm undecided to which oil grade will best suit my application. I'm leaning towards xw40s but I'm not certain it would be such a good idea since I still drive the car around town and oil temp hardly ever goes over 180F during these times. Is it a good idea to use the xw40 given my circumstance? I also want to know if I should go with a higher weight for the track? Thanks.