I read this post with two freinds of mine that go to tech school with me and it was agreed that that the BER will not change MPG. AT ALL! PERIOD. Its for less robbing of HP.
Just my opinion, and yours is yours.
And Restrictive headers...now that I think about it..I dunno? Maybe im just an idiot..or maybe the fact that typically a more restrictive exhaust yields more MPG than one that doesn't have it...example stock USspec headers for M3 vs...EU spec headers.. C'mon think about...don't try to make me look stupid, I do cars for a living u piss-wad.
(Not to mention other things that aren't required for EU as opposed to US and CARB emissions, egr, evap. All those systems are alot more restrictive and give less power..which I usually see as more MPG.
My opinion so move on or F*ck off...
