Looking at buying the aFE Power Mach Hi-Tuck Cat-Back exhaust and I see there's two options... a 2.5" pipe and a 3.0". Am I going to notice any real difference in sound or performance between the two sizes? An extra half inch is another 50 dollars.

 

I would stay with the 2.5" you need engine back pressure to generate torque. Too much free flow exhaust will produce more HP but a loss in torque. I prefer equal amounts of both for well rounded performance.

 

What he said. 3" for a V8 otherwise you'll lose a lot of torque. 2.5" seems to be the magical number for a naturally aspirated V6 motor 3.0L and bigger. A small v6 and a 2.25 maybe better.

A larger diameter exhaust pipe will move the power up higher in the rpm range...good for racing around a track....bad for offroad and normal street driving.

Best bang for the buck? Re-gear.

Sent from some string and a few tin cans.

 

Agree. Go with the 2.5" to keep backpressure.