My experience, for what it's worth:
When I bought my Corvette, new in 2005, I got out the Preparation H and prepared to go to the insurance office for coverage, knowing three things:
1. Plastic car.
2. Two seater
3. 400 HP in a 2800 pound car
4. High performance
I was pleasantly surprised that it was the cheapest car of my four to insure!
I told my agent that I was surprised it wasn't more expensive. He said "just be glad you didn't buy a Mustang." When I asked why he told me because of the statistics, i.e. they get wrecked a lot more. Evidently there aren't many Vettes in wrecks, which was somewhat comforting.
So State Farm, at least in Oklahoma, doesn't go by HP or power, they go by statistics, and driving record, age, sex, etc. Since not many 50 somethings have wrecks, I got a break, more than the Trac, the Pilot and the Expedition. Cool!