Want to install a free flow muffler on my....

'00 Volvo S40/168HP/Turbo. I am trying to maximize my MPG, not to be able to make noise! I have gone the SYN oil/atf route, the max pressure low RR tires,the K&N FIPK and obviously,learning how to drive very economically!!!!!! I am thinking about installing a universal Walker Quiet Flow Muffler sized to match my OEM muffler. This free flow muffler is supposed to be very quiet and produce 20-30% less back pressure than average OEM mufflers!!!??? Will this setup work? Would like some feedback! I subscribe to the KISS principal thus I will not spend big bucks on some elaborate exhaust system!!!! Thanks in advance TN

The oval-body Magnaflow mufflers are relatively quiet and offer low backpressure. I'm sure they have a size for your car.

And if I were trying to maximize MPG, I would remove everything that wasn't needed. If you don't ferry passengers, take out the seats and upholstery. If you can afford it, replace the OEM wheels to something lighter. Bigger usually means heavier - 16" is fine.

And with a turbo, a mandrel-bent 2.5"-3" exhaust system would be nice.