It's hard to say, as the NCAP ratings also come into it. The difference on the vehicle you have quoted will come down to cost to repair after an accident and likelyhood of being involved in an accident. It shows the opaqueness of insurance underwriting because the Corsa has more power, a larger engine, both are NCAP 4 - but because the Corsa is a lower insurance group, I would expect both cars to be very similar in quotes to be obtained. The price difference in a group 6 to 11 is negligible. It is all the other factors added to the car grouping that affects the premium on the grouping.