i never bothered to measure it , just fill up when CHEAP !
i keep the tire pressures set right & drive THE speed limit on the 401 ( save 10% for sure over 120km/h )
gooserex went with no-resonator to improve power & sound . i would like to hear his car as I went with a 2.5" Cherrybomb Glasspack from canadian tire . this eliminated the standard 2.5L contour resonator that crimp's the center pipe down to 2" ! i definetly picked up 1-2hp & have less restriction .
to answer your latest question : i would NOT go with a dual-exhaust for these reasons 1- this will add weight & penalise your economy 2- you do not have the high-flow intake to take advantage of the dual exhaust requirments .
i would just add either or both of a glasspack ( way cheaper than the magnaflow ) resonator & high-perf muffler .
have a local garage install it , not advanced stuff ... i paid $40 to do just the resonator .
btw , i use ESSO 91 , not injection problems & i get tiger points !
