Summer time oil change

The time to change my oil has come and because i will be installing a sohn adapter i was thinking using Castrol gtx 10w-40 or 15w-40 insted of idemitsu 10w-30 cause i am not going to be burning from my oil pan anymore plus summers here get as hot as 45c/113F. Should i use Castrol or pay for the much more expensive idemitsu