Hmm..I agree with Abdullah and Autophile has made a good point also in this discussion.
For the 1.3 and 1.6 Corollas - 10w40 or even 20w40 is good for khi and lhr hot weather
For the 1.8 new engine - 10w30 is ideal and 5w40, also fine
That being said, in my opinion, for the first oil change at 1,000 km, there is no need to put a fully synthetic oil (5w30, 5w40) as the next oil change will be at 5,000 km anyway. 10w30 is fine in this regard, as we are only paying extra for 5w40 due to the VI (viscosity index) improver, polymers that make up synthetic oil.
END OF THE DAY it's the car owner's choice - just make an informed decision.