Originally Posted by minxguy

260 degrees is not too high. Oil blenders test oil for viscosity at 210. 50 degrees above test temp is nothing. As I stated on another thread I personally have seen oil hot enough to bury a temp gauge that went to 345 F. Oil must be hot, first to cook off condensation, and second, some additives in oil are temp sensitive. if the oil isn't getting hot enough some additive packages won't work as they were designed to. If you are running at WOT and the temp is under 300 , your're fine. If you are running over 300 you may need to run a small cooler, but don't overcool. Now in regards to different oils running "cooler". You will have to agree that changing oil does not change you carb or FI settings, nor does it change your engine timing or boost or anything that could change combustion temps. So it could be safe to say that baring any changes in the aforementioned componets your engines combustion temps are pretty consistent for a given RPM. One of the duties that an engine oil must perform is to remove combustion heat from the internal engine parts and transfer that heat to the sump. So if your engine combustion temp stays at a given temp (realitive to RPM) and your sump temps decrease after changing to a different oil (synthetic or petroleum) the combustion heat isn't being transfered to the oil. The majority of this extra heat is going out the exhaust and the balance is being transfered to the surrounding metal, valves, piston crowns, etc. So even though you oil temp is less your internal engine componets could be running hotter. If you would like to discuss further ..call 1-800-243-8645, 7:30-3:30 M-F. Thanks, Ken