Easy answer (for me), my ex 2007 Mustang V8 had 305 hp + 4.6 L and Camaro V6 has 304 and 3.6 L
Mustang V8 is limited at 240 km/hour (I have checked by myself) and there is no reason for me to change to another V8 with more liters and HP.
Actually here in Spain, 1 liter of 95 Oct. gas = 1.04 EUR (rate exchange currently EUR/USD is 1.44 EUR=1 USD)