what engine oil should i use for my 1.4 8v ibiza (same engines as the polos but prob get a better response on here)

do i use 10w/40 semi synthetic or could i use 15w/40 mineral as its done 104500 miles and not sure wen it was last changed as I've dun over 6k miles since owning it.

I've used the 15w/40 in my old 1.3 mk2 golf which also had over 100k on the clock and wondering if it was ok to use that

I'd guess it would be 10/40. But the manual for the car should say what is best for it.