Well man, it depends. The stock 4.0 is a decent engine for being just a 6, but it has its limits. 05Horse has one of the sexiest mustangs I have seen and its a v6 with a S/C but with the 4.0 and the supercharger he is pushing out a little over 340 horses which in itself isnt bad, but the 4.6 makes about that much with a CAI a better exhaust and a tune. Also, the 4.0 has its limits, its no 350z... For the money I'd say save up for the 4.6 and a better suspension (make it a good suspension im personally a Steeda guy but take your pick) 4.6 + suspension = mid to high 12s allll dayy :bigthumbsup But it is totally your call man, just my .02
There is a lot more knowledgeable guys on this forum than me, so don't just listen to my advice. But personally im a v8 man, my dad has an 06 v6 and absolutely loves it, but to each his own i guess
There is a lot more knowledgeable guys on this forum than me, so don't just listen to my advice. But personally im a v8 man, my dad has an 06 v6 and absolutely loves it, but to each his own i guess