Exhaust tubing diameters - 3.0i vs 4.4i vs 4.6is vs 4.8is

[jcorreanyc]

So I have a 4.6is and I put an x-pipe on today. Sounds great but I want just a little more rumble. I'm thinking about putting on a pair 4.8is mufflers. It's a different part number with different looking cans. Does anyone know if this is a direct swap (bolt on with same hangers)?

I have read about it being 63mm tubing on the 4.8is. Not sure about the 4.6is. The 2.25 inch magnaflow fit baggy around the stock pipes on my car. 2.5 inches converted to mm = 63.5. So either the x-pipe came 2.5 inches or the pipes on the 4.6is are smaller. Doesn't make sense.

I've looked under both cars and they look exactly the same to me. Any knowledge is appreciated!