Which oil should i use for max. protection under high heat , service here told me to use ELF's 10-60 %100 Syn. , here Istanbul is quite hot city , the temp never drops below 0c at the winter times , how about Motul's 300V 15-50 or Motul's 5100 15-50 ? any difference between half syn. and full syn. ? please share some infos on "selecting the right oil" ...