Thought I'd try V power.

[Dead Eye]

True, but neither are what I would call performance engines... the V6 tries but realistically its still entry level

I imagine they have been developed to support the most common fuel available for the regions they are intended to be sold in. The KV6 has knock sensors but apparently the ECU will only compensate for lower RON fuels to avoid pinking and therefore won't make the most out of the likes of V-Power - this could go a way to explaining why remapping the ECU gets recommended