If you ever come across a 240 that has a "deep and mellow" sound have them lift the hood and see whose V8 they are running. 4 cylinder engines just don't lend themselves to "deep" or "mellow". Look at the ricers' sound from their 4's- choirboy high and chainsaw like. You might want to look at some of their exhaust systems as they claim to get incredible performance enhancements by bolting on one of those systems (grin).

Volvo's b230f engines are great engines but if it is significant performance increase that floats your boat you are going to have to think turbo charger. If increased performance and a "Hey, look at me" sound is important to you keep your eye open for a 240/740 drawing some serious portions of air through eight cylinders.

Randy