For a street car, you can use Castrol Edge 5w-30. When it is on sale, it doesn't break the wallet and being less viscous than the Penrite 5w-40, it should have better response. Change it at the 6 month/10,000km interval as recommended in your service booklet. Eventhough the bottle says it is a synthetic, it is a group III hydrocracked one and does not have the longevity of a real synthetic. It should withstand oil breakdown better than the Penrite semi synth though.

5w-40 is fine for the Jazz. It is slightly more viscous than stock (10w-30), which is probably why you feel it is less responsive.