In the summertime my oil has gotten up to 244-246 on regular Valvoline oil in the 10-30 weight as well as the 20-50. So the synthetic blends might be a good choice, right? With the 20-50 sometimes on a cold start I can hear the lifters knock a little(this happens when the weather gets colder at night, (fall, or winter time) Talat 97 GLX Blk/Blk