smokey1,
I'd stay with the OEM filter until the Yaris is out of warranty. Going to Fram, STP, Purolator etc. will only cancel out the warranty and IF someting goes wrong they're gonna leave you hanging.
Once it's outta warranty you free to use anf other brand you choose. I personaly use Fram "orange box" filters in my 89' Camry 4 cylinder AND change them out every 6 months. Despite what others have said I've always had good luck with Fram. Purolator is a fine version too and was told that STP is decent in addition.
Durango